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1
Hsieh, Hung-Yen, Ming-An Lee, Wei-Lun Chiu, and Pei-Jie Meng. "Comparison of Abundance and Structure of Larval Fish Assemblages between Autumn and Spring in the Waters Surrounding Taiwan Bank, Western North Pacific." Fishes 9, no. 1 (December 29, 2023): 16. http://dx.doi.org/10.3390/fishes9010016.
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The fluctuations in both time and space of larval fish assemblages in relation to hydrographic characteristics in the waters surrounding Taiwan Bank were studied in October 2021 (autumn) and March 2022 (spring). Throughout the study period, we identified a total of 149 taxa of fish larvae, encompassing 96 genera and 71 families. Engraulis japonicus, Diaphus slender type, unidentified Gobiidae, Apogon sp., unidentified Clupeidae, and Benthosema pterotum were the six dominant taxa and together constituted 47.39% of the total catch. There were no notable temporal variations observed in the abundance of fish larvae, but the species number of fish larvae was greater in spring than in autumn. Significant variations in species composition were observed between the different cruises, and the cluster analysis unveiled a distinct temporal structure of the assemblages of fish larvae. The dynamics of the prevailing currents induced by seasonal monsoons contribute significantly to the transportation of fish larvae. The distribution of fish larvae showed a good association with hydrographic characteristics, where seawater temperature and salinity emerged as the primary explanatory factors influencing the composition of larval fish assemblages in the waters surrounding Taiwan Bank. While the increased influx of nutrients from upwelling ensures abundant food availability, the hydrographic conditions may not be suitable for every fish larva.
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Puspasari, Reny, Ario Damar, M. Muklis Kamal, DTF Lumban Batu, Ngurah Nyoman Wiadnyana, and M. Taufik. "DINAMIKA LARVA IKAN SEBAGAI DASAR OPSI PENGELOLAAN SUMBER DAYA IKAN DI LAGUNA PULAU PARI KEPULAUAN SERIBU." Jurnal Kebijakan Perikanan Indonesia 5, no. 1 (May 31, 2013): 1. http://dx.doi.org/10.15578/jkpi.5.1.2013.1-7.
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Proses rekruitmen populasi ikan sangat ditentukan oleh kelangsungan hidup larva ikan yang ada di daerah pemijahan/asuhan. Laguna Pulau Pari merupakan daerah pemjahan bagi banyak jenis larva ikan karang. Tujuan dari penelitian ini adalah untuk mengkaji dinamika kelimpahan dan komposisi dari larva ikan di laguna Pulau Pari. Hasil penelitian menunjukkan bahwa kelimpahan larva ikan yang ditemukan berkisar antara 1,0 x103 – 14,7 x 103 individu/m3. Puncak kelimpahan tertinggi terjadi pada bulan Juli dan Oktober. Larva ikan ditemukan tersebar di semua lokasi pengamatan. Larva pada fase perkembangan pre flexion ditemukan dalam presentase yang paling tinggi. Selama masa pengamatan ditemukan 79 famili larva ikan yang didominasi oleh Pomacentridae, Aulostomidae, Blenniidae, Engraulidae dan Pinguipedidae. Dinamika yang terjadi pada larva ikan dapat dijadikan dasar bagi pengelolaan perikanan di wilayah Laguna Pulau Pari dengan cara memperluas daerah perlindungan laut dan rehabilitasi ekosistem Laguna Pulau Pari, sehingga peran dan fungsinya sebagai pemasok rekrut bagi stok ikan di perairan sekitarnya terjaga. Fish Recruitment is, in turn, thought to be directly related to the survival of the early life stages in the spawning/nursery ground. Pulau Pari Laguna is considered as a spawning ground for many reef fishes. The aims of the research were to investigate the dynamic of abundance and composition of fish larvae in Pulau Pari lagune. The Results show, fish larvae abundance range between 1,0 x 103 – 14,7 x 103 ind/m3. Highest larval abundance occurred on July and October, which predicted as the month of fish larvae production seasons. Fish larvae were distributed in all part of the lagune. Larvae in the pre flexion stage found in the highest precentation compare to other. Totally 79 families of reef fish larvae were found during June – November 2010 dominated by Pomacentridae, Aulostomidae, Blenniidae, Engraulidae and Pinguipedidae.
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Amri, Khairul, Atiah Al Mutoharoh, and Dwi Ernaningsih. "SEBARAN LARVA IKAN DAN KAITANNYA DENGAN KONDISI OSEANOGRAFI LAUT SULAWESI." Jurnal Penelitian Perikanan Indonesia 21, no. 2 (June 15, 2015): 103. http://dx.doi.org/10.15578/jppi.21.2.2015.103-114.
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<p>Laut Sulawesi diketahui sebagai daerah penangkapan ikan yang potensial sekaligus diduga sebagai lokasi pemijahan. Berbagai jenis larva ikan pelagis maupun demersal ditemukan di perairan ini. Kelimpahan dan sebaran larva ikan di suatu perairan sangat dipengaruhi oleh kondisi oseanografi seperti temperatur, salinitas dan sejumlah parameter lainnya termasuk ketersediaan pakan. Untuk mengetahui pengaruh parameter oseanografi terhadap kelimpahan dan sebaran spasial larva ikan di Laut Sulawesi, telah dilakukan penelitian menggunakan kapal riset KR Baruna Jaya VII pada Oktober 2012. Parameter oseanografi yaitu temperatur dan salinitas diukur menggunakan iCTD dan sampling larva menggunakan bonggo net pada 18 stasiun pengukuran. Analisa hubungan kondisi oseanografi dengan sebaran larva dilakukan secara deskriptif dan pemetaan sebarannya dilakukan secara spasial. Hasil menunjukan keterkaitan sejumlah parameter oseanografi dengan kelimpahan dan sebaran spasial larva ikan. Sebaran larva famili Scombroidae dominan berada pada perairan bersalinitas tinggi karena merupakan jenis ikan oseanik. Larva ikan demersal banyak ditemukan di perairan sekitar Kep.Sangihe Talaud. Kelimpahan larva tertinggi ditemukan di perairan bagian utara dan barat lokasi penelitian dimana kelimpahan plankton tinggi ditemukan.</p><p> </p><p>Celebes Sea is known as a potential fishing and spawning grounds for several pelagic fish species. Abundance and distribution of fish larvae are allegedly linked to oceanographic conditions such as temperature, salinity and others oceanographic parameters including food availablity. To see the effect of oceanographic on the abundance and spatial distribution of fish larvae in the Celebes Sea, has conducted a research in October 2012using the research vessel KR Baruna Jaya VII. The measurement of oceanographic parameters including temperature and salinity and larval sampling were done respectively by using iCTD and Bonggo net at 18 measuring stations. The analysis of data was carried out for dertemining the effect of oceanographic condition to the fish larvae distribution and distribution mapping spatially of larvae abundance. Results show that there were a connection between fish larvae abundance and spatial distribution with oceanographic parameters. Scombridae larvae distribution was dominant at waters with high salinity condition because they are oceanic. Demersal fish larvae are mostly found in waters around Sangihe-Talaud islands. Highest abundance of fish larvae was found at northern and western part of research locations where the higher plankton concentration was found.</p>
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Rinaldi, Rexa Kurnia, Niniek Widyorini, and Pujiono Wahyu Purnomo. "KOMPOSISI LARVA IKAN DI KAWASAN KOSERVASI MANGROVE DUSUN SENIK, DESA BEDONO, KECAMATAN SAYUNG, DEMAK." Management of Aquatic Resources Journal (MAQUARES) 6, no. 2 (March 9, 2018): 147–55. http://dx.doi.org/10.14710/marj.v6i2.19823.
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ABSTRAK Stadia larva merupakan fase pertumbuhan awal ikan. Distribusi dan Kelimpahan larva ikan di Ekosistem Mangrove merupakan proses rekruitmen alami. Kawasan Konservasi Mangrove Dusun Senik Desa Bedono merupakan daerah asuhan dan daerah mencari makan bagi larva ikan, saat ini daerah tersebut terkena abrasi. Hilangnya sebagian besar daratan memberikan pengaruh terhadap distribusi dan kelimpahan larva ikan. Penelitian ini bertujuan untuk mengetahui jenis, kelimpahan, dan sebaran larva ikan di kawasan konservasi mangrove Desa Bedono. Penelitian dilakukan di Kawasan Konservasi Mangrove Desa Bedono bulan September - Oktober 2016. Metode penelitian yang digunakan adalah survei dengan penentuan titik sampling secara purposive. Hasil yang diperoleh jumlah larva ikan yang tertangkap sebanyak 20.320 individu/150m3 yang terdiri dari 12 famili yaitu: Mugilidae (1.120 ind/150m3), Chanidae (20 ind/150m3), Gerreidae (60 ind/150m3), Apogonidae (17.360 ind/150m3), Scatophagidae (40 ind/150m3), Gobiidae (180 ind/150m3), Belonidae (40 ind/150m3), Ambassidae (20 ind/150m3), Lutjanidae (620 ind/150m3), Engraulidae (60 ind/150m3), Nemipteridae (40 ind/150m3), dan Oryziatidae (760 ind/150m3). Nilai kelimpahan larva ikan pada titik I sebesar 393 ind/150m3, titik II sebesar 607 ind/150m3, titik III sebesar 800 ind/150m3, titik IV sebesar 1.687 ind/150m3, titik V sebesar 1.633 ind/150m3, titik VI sebesar 607 ind/150m3, titik VII sebesar 235 ind/150m3, titik VIII sebesar 793 ind/150m3. Berdasarkan indeks morisita, pola sebaran larva ikan adalah acak. Kesimpulan yang dapat diambil adalah famili Apogonidae mendominasi dengan persentase 85,43%, nilai kelimpahan tertinggi terdapat pada titik IV, dan pola distribusi larva ikan menyebar secara acak yaitu keberadaan spesies tidak memiliki kecenderungan untuk hidup berkoloni dan dapat bertahan hidup di mana saja pada suatu ekosistem. Kata Kunci : Larva ikan; Komposisi; Kelimpahan; Pola Distribusi; Kawasan Konservasi Mangrove ABSTRACT Larval stage is the early growth phase of fish. Distribution and abundance of larval fish in mangrove ecosystem is a natural recruitment process. Mangrove Conservation Area at Senik hamlet Bedono village is the breeding and feeding areas for fish larvae, now the area is damaged by abrasion. The loss of the most mainland affects to the distribution and abundance of fish larvae. This study aims to determine the type, abundance and distribution of fish larvae in mangrove conservation area at Bedono village. The study was conducted in Bedono village Mangrove Conservation Area in September-October 2016. The research method that is used is a survey with purposive sampling point determination. The results obtained, the number of fish larvae caught are 20.320 individuals/150m3 consisting of 12 families, namely: Mugilidae (1.120 ind/150m3), Chanidae (20 ind/150m3), Gerreidae (60 ind/150m3), Apogonidae (17.360 ind/150m3), Scatophagidae (40 ind/150m3), Gobiidae (180 ind/150m3), Belonidae (40 ind/150m3), Ambassidae (20 ind/150m3), Lutjanidae (620 ind/150m3), Engraulidae (60 ind/150m3), Nemipteridae (40 ind/150m3), and Oryziatidae (760 ind/150m3). The value abundance of fish larvae in point I is 393 ind/150m3, in point II is 607 ind/150m3, in point III is 800 ind/150m3, point IV is 1.687 ind/150m3, point V is 1.633 ind/150m3, point VI is 607 ind/150m3, point VII is 235 ind/150m3, point VIII is 793 ind/150m3. Based on morisita index, the distribution pattern of fish larvae is random. The conclusion of this research are family Apogonidae dominates by percentage 85.43%, the highest abundance values is contained in point IV, and the distribution pattern of fish larvae randomly spread, means that the species does not live in colonies and can survive anywhere in an ecosystem. Keywords : Fish Larvae; Composition; Abundance; Distribution; Mangrove Conservation Area
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Wadjo, Amirudin, Frederika S. Pello, and Dicky Sahetapy. "POTENSI LARVA IKAN DI PERAIRAN TELUK KOTANIA, KABUPATEN SERAM BAGIAN BARAT." TRITON: Jurnal Manajemen Sumberdaya Perairan 19, no. 2 (October 30, 2023): 165–74. http://dx.doi.org/10.30598/tritonvol19issue2page165-174.
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The presence of fish larvae is one of the main factors for the sustainability of fish resources. Information on the potential of fish larvae is very useful for the conservation of fish resources. This study aims to analyze species composition (richness), individual abundance, the relationship of fish larvae abundance with physical-chemical parameters and formulate strategies and priorities for fish larvae management. The research was conducted in August and October at 8 stations. Potential data were analyzed using diversity index, uniformity index, dominance, and abundance of fish larvae. PCA analysis was used to assess the relationship between water quality parameters and fish larvae abundance. SWOT and AHP analysis were used to formulate management strategies and priorities. Based on the results, 9 genus/species of fish larvae belonging to 9 families, 5 orders of Class Osteichtyes were obtained. The abundance of fish larvae was highest in October. Serranus sp. and Siganus sp. larvae had high individual abundance. The parameters salinity, water temperature, current speed, PO4, SiO3, pH, water brightness, and DO have a correlation (+), meaning that these water quality parameters had a directly proportional relationship with fish larvae abundance. Eight strategies were formulated, with two primary priorities for the potential development of fish larvae in Kotania Bay waters, three secondary priorities and three tertiary priorities.
ABSTRAK
Keberadaan larva ikan merupakan salah satu faktor utama kelestarian sumberdaya ikan. Informasi tentang potensi larva ikan sangat berguna bagi kelestarian sumberdaya ikan. Penelitian ini bertujuan untuk menganalisis komposisi (kekayaan) spesies, kelimpahan individu, hubungan kelimpahan larva ikan dengan parameter fisik-kimia dan merumuskan strategi serta prioritas pengelolaan larva ikan. Penelitian dilakukan pada Agustus dan Oktober di 8 stasiun. Analisa data potensi menggunakan indeks keanekaragaman, indeks keseragaman, dominansi, dan kelimpahan larva ikan. Analisis PCA digunakan untuk mengkaji hubungan parameter kualitas air dengan kelimpahan larva ikan. Analisis SWOT dan AHP digunakan untuk merumuskan strategi dan prioritas pengelolaan. Berdasarkan hasil penelitian diperoleh 9 genus/spesies larva ikan yang termasuk dalam 9 famili, 5 Ordo dari Class Osteichtyes. Kelimpahan larva ikan tertinggi pada bulan Oktober. Larva ikan Serranus sp. dan Siganus sp. memiliki kelimpahan individu tinggi. Parameter salinitas, suhu air, kecepatan arus, PO4, SiO3, pH, kecerahan air, dan DO memiliki korelasi (+), yang berarti parameter kualitas perairan itu memiliki hubungan berbanding lurus dengan kelimpahan larva ikan. Dirumuskan delapan strategi, dengan dua prioritas primer pengembangan potensi larva ikan di perairan Teluk Kotania, tiga prioritas sekunder dan tiga prioritas tersier.
Kata Kunci: komposisi, kelimpahan, larva ikan, pengelolaan, Teluk Kotania
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Claus-Walker, Debra B., Philip H. Crowley, and Frank Johansson. "Fish predation, cannibalism, and larval development in the dragonfly Epitheca cynosura." Canadian Journal of Zoology 75, no. 5 (May 1, 1997): 687–96. http://dx.doi.org/10.1139/z97-089.
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We manipulated the risk of fish predation and cannibalism in semi-field and laboratory experiments with larvae of the dragonfly Epitheca cynosura. Results of a 22-week semi-field experiment showed that larvae from different densities were indistinguishable in mean size by the end of the experiment, but that individuals from low densities were larger until week 12. Larvae from low densities varied less in size than did those from high densities. Larvae showed rapid convergence of densities in the absence of fish. Fish predation also generated rapid convergence of densities. The presence of fish initially reduced larval size variation. There was a significant trend for the presence of fish scent to increase larval survival at low larval densities over survival in the absence of fish. Behavioral observations in the laboratory supported the results of the semi-field study in that (i) dragonfly larvae reduced their activity under daytime conditions, (ii) the presence of large larvae caused small larvae to increase their hiding inside a refuge and inhibited their crawling while exposed, (iii) small larvae ate fewer prey in the presence of fish. The results of our study suggest that the interaction between intra- and inter-specific predation risk may prove to be important for survival and development of animals in natural systems.
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Saraswati, Saraswati, Agus Hartoko, and Sasanti Retno Suharti. "HUBUNGAN KERAPATAN LAMUN DENGAN KELIMPAHAN LARVA IKAN DI PULAU PRAMUKA, KEPULAUAN SERIBU JAKARTA." Management of Aquatic Resources Journal (MAQUARES) 5, no. 3 (December 20, 2016): 111–18. http://dx.doi.org/10.14710/marj.v5i3.14397.
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ABSTRAKStadia larva merupakan fase awal daur kehidupan bagi ikan. Larva adalah biota perairan yang bersifat planktonik dan termasuk kedalam jenis meroplankton. Ekosistem Padang Lamun di Pulau Pramuka memiliki fungsi ekologis yang cukup penting di wilayah pesisir, dimana ekosistem ini merupakan salah satu daerah asuhan dan daerah mencari makan bagi larva ikan. Adanya perbedaan tingkat kerapatan lamun dan keberadaan makanan dapat memberikan pengaruh terhadap kelimpahan larva ikan. Sehingga hal tersebut menjadi landasan dilakukannya penelitian mengenai Hubungan Kerapatan Lamun Terhadap Kelimpahan Larva Ikan di Pulau Pramuka, Kepulauan Seribu Jakarta. Penelitian ini bertujuan untuk mengetahui kelimpahan larva ikan pada kerapatan lamun yang berbeda dan mengetahui pengaruh kerapatan lamun terhadap kelimpahan larva ikan. Metode yang digunakan adalah metode survei dengan penentuan titik sampling menggunakan metode purposive sampling. Hasil yang diperoleh adalah pada stasiun I tingkat kerapatan lamun padat (34156 individu/100m2) nilai kelimpahan larva ikan sebesar 756 individu/200m2 terdiri dari 8 famili. Stasiun II kerapatan sedang (26410 individu/100m2) nilai kelimpahan larva ikan yaitu 579 individu/200m2 terdiri dari 6 famili, dan stasiun III ketapatan jarang (6321 individu/100m2) nilai kelimpahan larva ikan sebesar 426 individu/200m2 yang terdiri dari 4 famili. Nilai korelasi antara kelimpahan larva ikan dengan kerapatan lamun yaitu sebesar r = 0,772. Berdasarkan hal tersebut dapat disimpulkan bahwa terdapat hubungan yang erat antara kelimpahan dan komposisi famili larva ikan dengan kerapatan lamun. Semakin tinggi nilai kerapatan lamun maka semakin tinggi pula nilai kelimpahan dan komposisi famili larva ikan. Begitu pula semakin rendah nilai kerapatan lamun maka nilai kelimpahan dan komposisi larva ikan juga semakin rendah. Kata Kunci : Kerapatan Lamun; Larva Ikan; Kelimpahan; Pulau Pramuka ABSTRACTLarval stage is the early phase of the life cycle for the fish. The larvae are aquatic biota that are planktonic and included into the type meroplankton. Seagrass ecosystems in Pramuka Island, has important ecological functions in coastal areas, where the ecosystem is one of the nursery ground and feeding ground for fish larvae. The big difference the density of seagrass and the presence of food can influence abundance of fish larvae. Thus, it will be the base for doing this research on The relations between Seagrass Density and Fish Larvae Abundance in Pramuka, Seribu Island Jakarta. This research aims to determine the abundance of fish larvae in different seagrass densities and determine the influence of the seagrass density on the abundance of fish larvae. The method used is survey method in determining the point of sampling using purposive sampling method. The results obtained are at station I the densities in dense seagrass (34156 individuals/100m2) abundance of fish larvae value at 756 individuals/200m2 consisting of eight families. Station II medium density (26410 individuals/100m2) the value of the abundance of fish larvae is 579 individuals/200m2 consisting of 6 families, and station III precision rarely (6321 individuals/100m2) the value of fish larvae abundance at 426 individuals/200m2 consisting of 4 families. The correlation values between the abundance of fish larvae with the density of seagrass in the amount of r = 0,772. Based on the above, we can conclude that there is a close relationship between the abundance and composition of fish larvae families with seagrass density. The higher the density of seagrass, the higher the families abundance and composition of fish larvae. Similarly, the lower the density value then the value of seagrass abundance and composition of fish larvae are also lower. Keywords: Sea Grass Density; Fish Larvae; Abundance; Pramuka Island.
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Lacerda, A. C. F., M. Santin, R. M. Takemoto, G. C. Pavanelli, A. Bialetzki, and F. C. Tavernari. "Helminths parasitizing larval fish from Pantanal, Brazil." Journal of Helminthology 83, no. 1 (March 2009): 51–55. http://dx.doi.org/10.1017/s0022149x08092171.
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AbstractFish larvae of ‘corvinas’ (Pachyurus bonariensis and Plagioscion ternetzi) from Sinhá Mariana Lagoon, Mato Grosso State, were collected from March 2000 to March 2004, in order to determine the parasitic fauna of fishes. Larvae from the two species were parasitized by the same endoparasites: Contracaecum sp. Type 2 (larvae) (Nematoda: Anisakidae) in the mesentery and Neoechinorhynchus (Neoechinorhynchus) paraguayensis (Acanthocephala: Neoechinorhynchidae) in the stomach and the terminal portion of the intestine. Statistical analysis showed that there was a significant positive correlation between the standard length of hosts and the abundance of acanthocephalans and nematodes, and that the prevalence of nematodes presented a significant positive correlation with the standard length of the two species of hosts, indicating the presence of a cumulative process of infection. The present study constitutes the first record of nematodes and acanthocephalans parasitizing larval fish, as well as the first record of endoparasites in fish larvae in Brazil. In addition, it lists a new locality and two species of hosts for Contracaecum sp. Type 2 (larva) and N. (N.) paraguayensis.
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Daryumi, Daryumi, Sahala Hutabarat, and Abdul Ghofar. "KOMPOSISI DAN DISTRIBUSI SPASIAL LARVA IKAN EKONOMIS PENTING DI PERAIRAN ESTUARI BANJIR KANAL TIMUR KOTA SEMARANG." Management of Aquatic Resources Journal (MAQUARES) 5, no. 3 (December 20, 2016): 91–97. http://dx.doi.org/10.14710/marj.v5i3.14394.
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ABSTRAK Perairan estuari Banjir Kanal Timur berfungsi sebagai daerah asuhan bagi larva ikan. Daerah estuari bersifat fluktuatif sehingga sifat-sifat fisik, kimia dan biologi bervariasi, pada fase larva ikan sangat menentukan kelangsungan hidup dari spesies ikan maupun populasi. Oleh karena itu, mengetahui keberadaan larva ikan ekonomis penting dapat memberi informasi tentang daerah mana yang dapat digunakan sebagai daerah penangkapan dan daerah mana yang harus dilestarikan. Penelitian dilakukan pada bulan Maret-April 2016 di Muara Banjir Kanal Timur Kota Semarang yang bertujuan untuk mengetahui komposisi dan distribusi spasial larva ikan. Metode yang digunakan yaitu metode Purposive Random Sampling. Hasil penelitian menunjukan jumlah rata-rata larva ikan sebanyak 1851 ind/150m3 terdiri dari famili Apogonidae, Mugilidae, Gerreidae, Lutjanidae, Engraulidae, Nemipteridae, Ambassidae, Gobiidae dan Chanidae. Jenis larva ikan yang yang paling banyak ditemukan adalah Mugillidae (Belanak) 38,92%, sedangkan yang paling sedikit adalah Chanidae (Bandeng) 0,38%. Larva ikan paling banyak tertangkap di daerah pantai (Titik III) dan yang paling sedikit tertangkap didaerah muara menuju sungai (Titik VI). Perhitungan indeks morista menunjukan larva ikan menyebar secara acak. Struktur komunitas larva ikan yaitu indeks keanekaragaman (H’) berkisar 0,64-1,66, indeks keseragaman (E) berkisar 0,14-0,39, dan indeks dominasi berkisar 0,21-0,67. Berdasarkan hasil uji regresi menunjukkan antara salinitas dengan kelimpahan larva ikan berkorelasi positif, sedangkan kecepatan arus dengan kelimpahan larva ikan berkorelasi negatif. Kata Kunci: Estuari; Larva Ikan; Komposisi; Distribusi; Banjir Kanal Timur Semarang. ABSTRACT The estuaries of eastern Banjir Kanal served as the nursery ground for fish larvae. Areas of estuaries were fluctuating. So the parameters of the physical, chemical and biological were variation, in fish larvae phas largely determine survival rate of fish species or populations. For it to, knowing the existence of economically important fish larvae could providing information about which areas be using as a capture area and which areas that should be preserved. Research conducted in March-April 2016 at the Eastern Banjir Kanal of Semarang, aims to find out the composition and spatial distribution of fish larvae. The method used Purposive Random Sampling method. The research showed the range number of larvae as 1851 ind/150m3 consists of Familia Apogonidae, Mugilidae, Gerreidae, Lutjanidae, Engraulidae, Gobiidae, Ambassidae, Nemipteridae and Chanidae. Types of fish larvae found the most high was Mugillidae (Mullet) 38,92%, while the least was Chanidae (Milkfish) 0,38%. The larvae of most fish caught in coastal areas (point III) and the least caught in the estuary towards the river (Point VI). The calculation of the index morista fish larvae spread randomly. Fish larvae community structures were the index of diversity (H ') range from 0,64-1,66, uniformity index (E) range 0,14-0,39, and dominance index range from 0,21-0,67. Based on the results of the regression analysis showed between salinity with an abundance of fish larvae correlating positively, where the current speed with an abundance of fish larvae correlating negatively.Keywords: Estuarie; Fish Larvae; Composition; Distribution; Eastern Banjir Kanal Semarang.
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Stoll, Stefan, and Peter Beeck. "Larval fish in troubled waters — is the behavioural response of larval fish to hydrodynamic impacts active or passive?" Canadian Journal of Fisheries and Aquatic Sciences 69, no. 10 (October 2012): 1576–84. http://dx.doi.org/10.1139/f2012-086.
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In a mesocosm experiment, we tested whether larval fish show an active behavioural response to hydrodynamic impacts. Exposing 1- to 3-week-old allis shad ( Alosa alosa ) larvae to a pulsed wave regime, we found that already 1-week-old larvae immediately adapt their microhabitat use and activity patterns at the onset of the wave pulses. The fish larvae instantaneously increased their activity level and moved downwards, concentrating in the calmer lower third of the water column. Within 4 min after the end of the wave pulse, the fish returned to their former distribution. Two- and 3-week-old fish larvae foraged close to the bottom substratum during calm periods but avoided this zone during the wave pulses. Thus, larval fish show an active response to hydrodynamic impacts. With the ability to adjust microhabitat use and activity level, already fish larvae are able to trade costs and benefits associated with spatio-temporal hydrodynamic heterogeneity. In particular, fish larvae should be able to minimize some of the harmful effects of navigation-induced waves where calmer evasion habitats are available.
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Manan, Abdul. "Kelimpahan Larva Ikan Pada Kondisi Air Pasang Dan Surut Di Muara Sungai Pilang Sari, Desa Pidodo Kulon, Kendal <br><i>[Abundance Of Fish Larvae In Neap And Tide Condition In Estuary Of Pilang Sari River, Pidodo Kulon Village, Kendal ]<i>." Jurnal Ilmiah Perikanan dan Kelautan 3, no. 2 (November 1, 2011): 249–54. http://dx.doi.org/10.20473/jipk.v3i2.11614.
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Abstract The aim of this research is to know the abundance of fish larvae in neap and tide condition in estuary of Pilang Sari river, Pidodo Kulon village, Kendal. This research is case study where the fish larvae that been caught was deeply observed in the limited time, place and population. Sample was taken in the three place. Data were collected used seine net when the neap and tide of sea level. The number of fish larva that been caught during the research are 12.983. Including from 8 genus are Stolephorus, Ambassis, Periapthalmus, Gerres, Leiognathus, Terapon, Atherinomarus. The composition of fish larvae that been caught when neap and tide was dominated by Stolephorus and Ambassis. When the new moon phase, the number of fish larvae that been caught is 1151, quarter moon is 2379, full moon is 5243 and three–quarters of the moon is 4110 fish larvae. The result of this research shows the relationship between the pattern of tide and amount of the fish larvae that been caught every moon phase. In the sping tide pattern, amount of the fish larvae that been caught was bigger than neap tide pattern. In commonly, fish larvae that been caught when the tide is bigger than abundance of fish larva that caught when the water was neap.
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Redjeki, Sri, Riska Novianti Putri, Adi Santoso, Sunaryo Sunaryo, and Sri Sedjati. "Komposisi Larva Ikan Pada Tutupan Padang Lamun di Perairan Prawean Bandengan, Kabupaten Jepara." Buletin Oseanografi Marina 8, no. 2 (October 4, 2019): 96. http://dx.doi.org/10.14710/buloma.v8i2.25639.
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Larva Ikan (ichtyoplankton) merupakan tahapan awal dari daur hidup ikan dimulai dari perkembangan telur, larva dan juvenil, memiliki tingkat mortalitas tinggi dan peka terhadap perubahan lingkungan, predator, dan kesediaan makanan. Fungsi ekologis padang lamun sebagai daerah asuhan dan tempat berlindung bagi semua jenis organisme laut kecil, salah satunya larva ikan. Kerapatan atau tutupan padang lamun juga sebagai salah satu faktor pendukung melimpahnya organisme dan kekayaan di laut. Tujuan Penelitian ini untuk mengetahui kelimpahan dan distribusi larva ikan yang terdapat pada ekosistem padang lamun, serta mengetahui hubungan kelimpahan larva ikan dengan tutupan padang lamun di Perairan Prawean Bandengan, Jepara. Metode penelitian ini adalah metode deskriptif dengan penentuan lokasi sampling menggunakan purposive sampling methode. Lokasi penelitian pada 3 stasiun dengan pembagian kerapatan lamun yang berbeda (I = Padat ; II = Sedang ; III = Jarang) dan dilakukan sebanyak 3 kali pengulangan sampling di masing-masing lokasi. Pengambilan sampel larva ikan dilakukan dengan menggunakan larva net (P = 0,9 m ; L : 0,6m) dengan ukuran mata jaring 800 µm. Hasil penelitian ini ditemukan larva ikan sebanyak 5 famili yaitu Nemipteridae, Gerreidae, Gobiidae, Labridae, dan Mullidae. Famili larva ikan yang paling sering ditemukan adalah Nemipteridae. Rata-rata kelimpahan famili larva ikan pada Stasiun I sebesar 0,419 ind/m3, Stasiun II sebesar 0,205 ind/m3, dan pada stasiun III sebesar 0,069 ind/m3. Nilai rata - rata indeks keanekaragaman termasuk dalam kategori rendah sedang (0,65–1,37), indeks keseragaman larva ikan termasuk dalam kategori rendah-tinggi (0,33-0,65) indeks dominasi larva ikan menunjukan ada yang mendominasi pada tiga stasiun (0,28–0,30) dan indeks sebaran morisita yang dilakukan menunjukan bahwa sebaran larva ikan pada tiga stasiun merata. Fish larvae (ichtyoplankton) are the initial stages of the fish's life cycle starting from the development of eggs, larvae and juveniles, which have a high mortality rate and are sensitive to environmental changes, predators, and food availability. The ecological function of seagrass beds as nurseries and shelter for all types of small marine organisms, one of which is fish larvae. The density or cover of seagrass beds is also one of the supporting factors for the abundance of organisms and wealth in the sea. The purpose of this study was to determine the abundance and distribution of fish larvae found in the seagrass ecosystems, and to determine the relationship of abundance of fish larvae with cover seagrass beds in the waters of Prawean Bandengan, Jepara. This research method is a descriptive method by determining the sampling location using purposive sampling method. The research location was in 3 stations with a different distribution of seagrass density (I = Dense; II = Medium; III = Rare) and carried out 3 times repetition of sampling at each location. Sampling of fish larvae was carried out using larvae net (P = 0,9 m; L: 0,6m) with a mesh size of 800 μm. The results of this reasearch, found fish larvae of 5 families, namely Nemipteridae, Gerreidae, Gobiidae, Labridae, and Mullidae. The most common family of fish larvae was Nemipteridae. The average abundance of fish larvae at Station I was 0,419 ind/m3, Station II was 0,205 ind/m3, and at Station III was 0,069 ind/m3. The average diversity index was included in the low category (0,65 – 1,37), the uniformity index of fish larvae was included in the low-high category (0,33 – 0,65) the fish larvae dominance index shows that there are dominating at three stations (0,28 – 0,30) and the distribution index of distribution (morisita) conducted showed that the distribution of fish larvae at three stations was evenly distributed.
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Hidayaturrohmah, Fitriana, Bambang Sulardiono, and Wiwiet Teguh Taufani. "KELIMPAHAN LARVA IKAN BERDASARKAN FASE BULAN DI PADANG LAMUN PANTAI PRAWEAN, JEPARA." Management of Aquatic Resources Journal (MAQUARES) 7, no. 4 (October 15, 2018): 431–39. http://dx.doi.org/10.14710/marj.v7i4.22666.
Full textAbstract:
Perairan Prawean Jepara, merupakan salah satu wilayah pantai dengan garis pantai terluas di pesisir Jepara. Kondisi morfologi yang terdapat pada pantai ini memiliki komunitas padang lamun yang relatif subur yang mempengaruhi kelimpahan larva ikan. Larva ikan merupakan tahap awal dari pertumbuhan ikan. Larva juga dipengaruhi oleh banyak faktor lingkungan bagi kelulushidupannya. Fase bulan yang berhubungan dengan pasang surut akan mempengaruhi hasil dari kelimpahan larva ikan. Penelitian ini bertujuan untuk mengetahui jenis dan kelimpahan larva ikan pada kerapatan lamun di fase bulan yang berbeda. Penelitian dilaksanakan pada bulan Maret - April 2018. Metode yang digunakan adalah metode survei dengan penentuan titik sampling menggunakan metode purposive sampling di 3 stasiun baik pada saat pasang dan surut di fase bulan berbeda. Hasil yang diperoleh menunjukkan bahwa jumlah larva ikan yang tertangkap sebanyak 1382 ind/900m3 terdiri dari 8 famili yakni: Apogonidae (7), Blennidae (415), Engraulidae (34), Gobiidae (521), Lutjanidae (218), Mugillidae (60), Mullidae (25) dan Nemipteridae (102). Larva famili yang tertangkap secara keseluruhan, Gobbidae (larva yang paling banyak tertangkap) dan Apogonidae (jumlah paling sedikit). Nilai korelasi antara kelimpahan larva ikan dengan kerapatan lamun yaitu sebesar r = 0,546; 0,628; 0,784 dan 0,791. Berdasarkan hal tersebut dapat disimpulkan bahwa terdapat hubungan yang erat antara kelimpahan dan komposisi famili larva ikan dengan kerapatan lamun. Prawean Jepara waters are one of the coastal areas with the widest coastline on the coast of Jepara. The morphological conditions found on this beach relatively has fertile seagrass communities that affect the abundance of fish larvae. Fish larvae is the initial stage of fish growth. Larvae is also influenced by many environmental factors for their life. The phases of the moon associated with tides will affect the results of the abundance of fish larvae. This study aims to determine the type and abundance of fish larvae in seagrass density in different moon phases. The study was conducted in March - April 2018. The method used was a survey method with the determination of sampling points using purposive sampling method at 3 stations both at high tide and low tide in different moon phases. The results obtained showed that the number of fish larvae caught was 1382 ind/900m3 consisting of 8 families: Apogonidae (7), Blennidae (415), Engraulidae (34), Gobiidae (521), Lutjanidae (218), Mugillidae (60) , Mullidae (25) and Nemipteridae (102). The family find overall larvae, Gobbidae (the most caught larvae) and Apogonidae (is the least caught larvae). The correlation value between the abundance of fish larvae with seagrass density is equal to r = 0.546; 0.628; 0.784 and 0.791. Based on this, it can be concluded that there is a close relationship between abundance and composition of fish larvae families with seagrass density.
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Measures, Lena N. "Epizootiology, pathology, and description of Eustrongylides tubifex (Nematoda: Dioctophymatoidea) in fish." Canadian Journal of Zoology 66, no. 10 (October 1, 1988): 2212–22. http://dx.doi.org/10.1139/z88-329.
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In Guelph Lake, a man-made reservoir in Ontario, Canada, prevalence of larval Eustrongylides tubifex in pumpkinseed (Lepomis gibbosus), rock bass (Ambloplites rupestris), and yellow perch (Perca flavescens) was 12.9% and mean intensity ranged from 1 to 1.8. Larvae were encapsulated on the mesentery of fish. Pumpkinseed and yellow perch were the important fish hosts in Guelph Lake as most larvae in these fish were alive. In contrast, 40% of larvae in rock bass were dead and calcified. Third- and fourth-stage larvae from naturally infected fish are described. Larvae in the three species of fish elicited a granulomatous inflammatory reaction. Attempts to transfer third-stage larvae from experimentally infected oligochaetes and third-stage larvae from naturally infected fish to laboratory-reared pumpkinseed were unsuccessful. Fourth-stage larvae from naturally infected fish were transferred successfully to pumpkinseed. Eutropic lakes such as Guelph Lake are particularly suitable enzootic areas because of the abundant populations of tubificid intermediate hosts and the presence of fish hosts such as pumpkinseed and perch. The advanced stage and development of larvae (to the fourth stage) in fish likely represents an adaptation for a parasite that occurs in a migratory host such as Common Mergansers (Mergus merganser), which frequent Guelph Lake for only about 1 month in spring and fall.
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Asmiani, Asmiani, Sarjito Eko Windarso, and Siti Hani Istiqomah. "Kemampuan Predasi Ikan Sepat (Trichogaster trichopterus) dalam Memangsa Larva Anopheles sp." Sanitasi: Jurnal Kesehatan Lingkungan 4, no. 3 (February 14, 2013): 136–41. http://dx.doi.org/10.29238/sanitasi.v4i3.682.
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Malaria is still one of public health problems because it can lead to fatality, particularly among high risk groups, including infants, under five children and pregnant mothers. The utilization of larvae-eating fish for controlling mosquito larvae as biological method is highly recommended because it is safe and environmentally friendly. The objective of this study was to understand the predation capacity of sepat fish (Trichogaster trichopterus) on Anopheles sp larvae in the labo-ratory setting by conducting a true experiment of factorial with randomized groups design. There were six interventions as a result of the combination of three fish lengths (i.e. 4, 7 and 10 cm) and two water heights in aquarium (i.e. 10 and 100 cm). In each aquarium there were 10 larvaes and one healthy but three-day hungry fish, and for each intervention there was five replications. The number of larvae eaten by the fish was observed after 15 minutes. Result of the statistical test of one way anova multivariate test showed that predation capacities of sepat fish at various water levels and fish sizes were significantly different. Fish at 4 cm length in 10 cm water height had the highest predation capacity (mean: 9,2; SD: 1,09) compared with the other interventions. It is suggested that for further studies it is necessary to consider different research design as well as the other factors such as the size of larva instar, water type, and intervention time.
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RODRÍGUEZ-MAHILLO, ANA I., MIGUEL GONZÁLEZ-MUÑOZ, IGNACIO MONEO, M. TERESA SOLAS, ÁNGEL MENDIZÁBAL, CRISTINA de las HERAS, and MARGARITA TEJADA. "Allergenic Properties and Cuticle Microstructure of Anisakis simplex L3 after Freezing and Pepsin Digestion." Journal of Food Protection 71, no. 12 (December 1, 2008): 2578–81. http://dx.doi.org/10.4315/0362-028x-71.12.2578.
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This article examines the viability of and the alterations to the larval cuticle and the pattern of the antigens released when live or frozen Anisakis simplex larvae were treated with acid and pepsin. The results showed that freezing did not greatly alter the larva body. If ruptures were observed, the antigen release to the incubation media was not enhanced, and most of the antigenic content was retained inside the bodies of the larvae. The immunoblotting assay demonstrated that most of the antigens released, including the allergen Ani s 4, were resistant to pepsin. Freezing killed the larvae, but their survival was not compromised by acid treatment or pepsin digestion when kept chilled. All these findings support recommendations about freezing fish for consumption raw or undercooked to prevent human infection by A. simplex larvae. However, our data show that the antigenicity of the larvae is preserved after freezing and may explain why some sensitized patients develop symptoms after ingestion of infested frozen fish.
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Muller, U. K., E. J. Stamhuis, and J. J. Videler. "Hydrodynamics of unsteady fish swimming and the effects of body size: comparing the flow fields of fish larvae and adults." Journal of Experimental Biology 203, no. 2 (January 15, 2000): 193–206. http://dx.doi.org/10.1242/jeb.203.2.193.
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Zebra danios (Brachydanio rerio) swim in a burst-and-coast mode. Most swimming bouts consist of a single tail flick and a coasting phase, during which the fish keeps its body straight. When visualising the flow in a horizontal section through the wake, the effects of the flow regime become apparent in the structure of the wake. In a two-dimensional, medio-frontal view of the flow, larvae and adults shed two vortices at the tail during the burst phase. These vortices resemble a cross section through a large-core vortex ring: two vortex cores packed close together with the central flow directed away from the fish. This flow pattern can be observed in larvae (body length approximately 4 mm) at Reynolds numbers below 100 as well as in adult fish (body length approximately 35 mm) at Reynolds numbers above 1000. Larval vortices differ from those of adult zebra danios mainly in their relatively wider vortex cores (higher ratio of core radius to ring radius) and their lower vortex circulation. Both effects result from the increased importance of viscosity on larval flows. During the coasting phase, larval and adult flows again differ because of the changing importance of viscosity. The high viscosity of the water causes large vortical flows adjacent to the larva's body. These regions of high vorticity represent the huge body of water dragged along by the larva, and they cause the larva to stop almost immediately after thrust generation ceases. No such areas of high vorticity are visible adjacent to adult zebra danios performing a comparable swimming manoeuvre. The rapid decrease in vortex circulation and the severe reduction in the coasting distance due to viscous drag contribute to the high cost that larvae - unlike adult fish - face when using a burst-and-coast swimming style.
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Restiangsih, Y. H., I. M. Radjawane, A. Mamun, D. Kembaren, and E. Nurdin. "The relationship between Oceanographic Parameters and Fish Larvae Dispersal in the Fisheries Management Area of the Republic Indonesia (FMA) 717." IOP Conference Series: Earth and Environmental Science 925, no. 1 (November 1, 2021): 012032. http://dx.doi.org/10.1088/1755-1315/925/1/012032.
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Abstract Cendrawasih Bay and the Pacific Ocean are known as potential fishing areas and as fish spawning locations in Fisheries Management Area 717. Larval dispersal in the waters is strongly influenced by oceanographic parameters. This study was conducted to examine the relationship between oceanographic parameters and fish larval dispersal in FMA 717. This research was conducted using KR Bawal Putih III in November 2019. A number of 42 stations were determined for observation. Environmental parameters included temperature, salinity, dissolved oxygen, chlorophyll-a, turbidity, and photosynthetic active radiation (PAR), were measured using SBE 19 plus V2 CTD while pelagic fish larvae were collected using a bonggo net. Analysis of the correlation of oceanographic parameters with pelagic fish larvae abundance and spatial distribution was calculated using PCA (Principal Component Analysis) statistical analysis. The results showed that the pelagic fish larvae was influenced by temperature, salinity, PAR, chlorophyll-a, turbidity, and DO. Temperature and salinity have a direct interaction to the abundance of pelagic fish larvae.
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Køie, Marianne. "Aspects of the life cycle and morphology of Hysterothylacium aduncum (Rudolphi, 1802) (Nematoda, Ascaridoidea, Anisakidae)." Canadian Journal of Zoology 71, no. 7 (July 1, 1993): 1289–96. http://dx.doi.org/10.1139/z93-178.
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Gravid Hysterothylacium aduncum from the intestine of eelpout, Zoarces viviparus, were used as the source of eggs for study. The two first moults occurred in the egg, which does not normally hatch spontaneously. The third-stage larva within the egg was not infective to either fishes or non-crustacean invertebrates, but developed into a typical third-stage larva in Acartia tonsa, harpacticoid copepods, various amphipods, isopods, and mysids. Further development in the fish host was apparently dependent only on the length of the larva. Thus, larvae from harpacticoids (< 1 mm long) and larvae less than 1.5 – 2.0 mm long from other crustaceans did not survive in the fish; larvae between about 2 and 3 mm in length remained as third-stage larvae in the fish. Larvae longer than 3 mm moulted into fourth-stage larvae in the intestinal lumen of the fish. Thus, a two-host cycle occurs when fishes ingest crustaceans harbouring third-stage larvae longer than 3 mm, and a cycle of three (or more) hosts when fishes ingest third-stage larvae less than 3 mm long. Ctenophores, chaetognaths, polychaetes, and ophiuroids, which become infected by ingesting infected crustaceans, may act as obligate intermediate hosts or transport hosts.
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shoji, jun, tsutomu maehara, and m. tanaka. "larval growth and mortality of japanese spanish mackerel (scomberomorus niphonius) in the central seto inland sea, japan." Journal of the Marine Biological Association of the United Kingdom 85, no. 5 (October 2005): 1255–61. http://dx.doi.org/10.1017/s0025315405012403.
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growth and mortality rates of larval japanese spanish mackerel (scomberomorus niphonius) were estimated by using otolith daily increments in 1997 and 1998 in the sea of hiuchi, central seto inland sea. there was no day–night difference in the abundance and size-distribution of s. niphonius larvae in the 3–10 mm size-classes, indicating the larvae were efficiently collected by the larva-net used for sampling (1.3 m mouth diameter, 0.5 mm mesh). mean absolute growth rate (0.748 mm d−1 in 1997, 0.821 mm d−1 in 1998), weight specific growth coefficient (g: 0.402 in 1997, 0.444 in 1998) and mortality coefficient (m: 0.784 in 1997 and 0.625 in 1998) were among the highest reported for marine fish larvae. scomberomorus niphonius seems to have evolved survival strategies characterized by fast growth with strong piscivory that can reduce duration of the larval period with the high mortality. in 1997, spatial distribution of the larvae was not well corresponded to that of their prey, clupeid larvae, and the larval feeding incidence was lower than in 1998. recruitment potential assessed by examining the ratio of g:m was lower in 1997 (0.513 in 1997, 0.711 in 1998) due to the lower g and higher m values. prey fish availability may be one of the important determinants for the recruitment potential by controlling the larval mortality due to starvation and/or starvation-related predation.
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Kusumawathie, P. H. D., A. R. Wickremasinghe, N. D. Karunaweera, and M. J. S. Wijeyaratne. "Larvivorous Potential of the Guppy, Poecilia reticulata, in Anopheline Mosquito Control in Riverbed Pools Below the Kotmale Dam, Sri Lanka." Asia Pacific Journal of Public Health 20, no. 1 (January 2008): 56–63. http://dx.doi.org/10.1177/1010539507308507.
Full textAbstract:
The larvivorous potential of Poecilia reticulata was studied in the laboratory and in the field. In the laboratory, the number of anopheline larvae consumed per fish per day and the number of larvae in fecal matter per fish were determined. In the field study, 29 of 60 selected riverbed pools in Kotmale oya, below the Kotmale dam, were stocked with P reticulata, whereas the rest served as controls. Anopheline larval surveys were carried out starting from 1 day prior to stocking of fish and on selected days subsequently. P. reticulata consumed an average of 117 ± 32.33 larvae per fish per day. Fecal matter of P. reticulata contained an average of 2.7 ± 2.68 larvae per fish . There was a significant reduction in the number of pools positive for anopheline larvae ( P < .001) after stocking fish and the number of larvae per pool ( P < .001) and per 100 dips ( P < .001) as compared with controls.
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Prianto, Eko, Syarifah Nurdawaty, and Mohammad Mukhlis Kamal. "DISTRIBUSI, KELIMPAHAN DAN VARIASI UKURAN LARVA IKAN DI ESTUARIA SUNGAI MUSI." BAWAL Widya Riset Perikanan Tangkap 5, no. 2 (March 16, 2016): 73. http://dx.doi.org/10.15578/bawal.5.2.2013.73-79.
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Penelitian tentang distribusi, kelimpahan dan ukuran larva ikan dilakukan pada bulan Maret, Mei, Juni dan Oktober 2011. Stasiun pengambilan contoh meliputi Muara Delta Upang (stasiun 1), Muara Sungai Musi (stasiun 2) dan Pulau Payung (stasiun 3). Pengambilan larva pada siang hari menggunakan Bongo net yang berukuran mata jaring 250 µm. Hasil identifikasi diperoleh 13 famili ditinjau menurut musim, pada bulan Mei dan Oktober masing-masing diperoleh 7 famili, dan pada bulan juni sebanyak 3 famili. Kelimpahan larva ikan berkisar antara 9-46 ind/m3 dengan jumlah yang tertinggi (46 ind/m3) pada bulan Mei dan terendah pada bulan Juni (9 ind/m3). Larva ikan dari famili Gobiidae memiliki sebaran yang cukup luas baik spasial maupun temporal. Variasi ukuran larva ikan menurut famili setiap bulannya memiliki variasi ukuran yang hampir sama. Research about the distribution, abundance and size of fish larvae was conducted in March, May, June and October 2011. Sampling stations encompasses Delta Upang (station 1), Muara Sungai Musi (station 2) and Pulau Payung (station 3). Larvae taken during the daytime using a Bongo net with mesh size of 250 µm. Identification results obtained 13 families based on the season, in May and October respectively 7 families, and in June as many as 3 families. Abundance of fish larval around 9-46 ind/m3 with the highest number (46 ind/m3) in May and the lowest in June (9 ind/m3). Larvae of Gobiidae family have a large distribution on spatial and temporal. The variation in size of fish larvae by family on each month are the same.
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ÁLVAREZ-GUERRERO, CESAR, and FERNANDO ALBA-HURTADO. "Effect of Some Physical Factors on the Viability of Third-Stage Gnathostoma binucleatum Larvae." Journal of Food Protection 74, no. 5 (May 1, 2011): 844–48. http://dx.doi.org/10.4315/0362-028x.jfp-10-321.
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To diminish the risk of transmission to humans of advanced third-stage larvae (A3L) of Gnathostoma binucleatum in fish foods, we evaluated the effects of some physical factors on larval viability. A3L protected within fish meatballs were subjected to freezing, refrigeration, boiling, dry heat, and immersion in lemon juice. By freezing, larvae were killed in 48 h, by refrigeration after 30 days, by boiling in 4 min, and by broiling for 60 min. By lemon juice immersion (pH 2.5), encysted larvae were killed after 5 days and nonencysted larvae in 7 h. Results show that freezing fish at −10 to −20°C for 48 h, or cooking fish by frying, boiling, or broiling, will prevent transmission of G. binucleatum. Furthermore, results dispel the popular myth that lemon juice kills encysted larvae in fish.
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Le, Quoc Viet, Van Khanh Ly, Thi My Han Duong, Nguyen Duy Khoa Tran, Tomonari Kotani, and Ngoc Hai Tran. "Effects of rotifer densities on larval performance of spotted scat (Scatophagus argus)." Can Tho University Journal of Science 13, Aquaculture (June 30, 2021): 37–43. http://dx.doi.org/10.22144/ctu.jen.2021.015.
Full textAbstract:
This study is aimed to determine the optimal rotifer feeding density for larviculture of spotted scat fish (Scatophagus argus). The experiment was randomly set up in triplicate with 5 treatments including 5, 10, 15, 20 and 25 rotifers/mL. The fish larvae with the initial body length and depth at 2,343 ± 110 µm and 812 ± 85µm, respectively, were stocked in 250-L tanks at 10 larva/L of density and 25‰ of salinity. After 21 days of rearing, the results showed that the larval growth were at 243 – 330 µm/day of DLG and 5.50 – 6.70 %/day of SGRL; 131 –204 µm/day of DDG and 7.20 – 8.93 %/day of SGRD, but no significant difference in larval growth performance was recorded among treatments (p>0.05). However, the highest survival rate of fish larvae (35.4-48.1%) was recorded in the treatments fed 5 and 10 rotifers/mL and was significantly higher than other treatments (p<0.05). The data demonstrated that spotted scat larvae fed effectively across as wide range of rotifer densities and the range at 5-10 rotifers/mL were suggested for the husbandry practices.
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Melianawati, Regina, Ni Wayan Widya Astuti, and Tridjoko Tridjoko. "Peranan Taurin pada Pertumbuhan dan Kelangsungan Hidup Larva Ikan Kerapu Bebek Cromileptes altivelis (Valenciennes, 1828)." Jurnal Kelautan Tropis 26, no. 1 (September 2, 2022): 27–34. http://dx.doi.org/10.14710/jkt.v26i1.13490.
Full textAbstract:
Taurine is an important amino acid for the growth of marine fish larvae The humpback grouper (Cromileptes altivelis) is a highly valuable marine fish that has been farmed in hactheries. The increasing of larval growth and survival rate of humpback grouper was carried out by taurine addition as enrichment ingredient to zooplankton as live feed for larvae. The purpose of this study was to find out the role of taurine on larval growth and survival rate. Two treatments tested were taurine addition by bioencapsulated through zooplankton rotifers Brachionus rotundiformis (A) and without taurine addition in rotifers (B). The observed parameters were larval growth and survival rate. Larval samples were taken on day 1 and 5, then continued every 5 days until the end of the study, by using10 larval samples at each time. The results showed that mostly all larvae have already metamorphosed and become juveniles at 35 days old. At that time, larvae with taurine addition (A) have bigger in size, faster growth and also higher survival rate compared than larvae without taurine addition(B). Therefore, the result of this study indicated that the addition of taurine could improve larval growth and the survival rate of humpback grouper. Taurin merupakan asam amino penting untuk pertumbuhan larva ikan laut. Ikan kerapu bebek (Cromileptes altivelis) adalah salah satu jenis ikan laut bernilai ekonomis tinggi yang sudah dapat dibudidayakan. Peningkatan pertumbuhan dan kelangsungan hidup larva ikan kerapu bebek dilakukan dengan penambahan taurin sebagai bahan pengkaya ke dalam zooplankton sebagai pakan alami larva. Tujuan penelitian ini adalah mengetahui peranan taurin pada pertumbuhan dan kelangsungan hidup larva. Dua perlakuan yang diujikan adalah penambahan taurin melalui bioenkapsulasi pada zooplankton rotifer Brachionus rotundiformis (A) dan tanpa penambahan taurin pada rotifer (B). Parameter yang diamati adalah pertumbuhan dan kelangsungan hidup larva. Sampel larva diambil pada umur 1 dan 5 hari, selanjutnya setiap 5 hari sekali hingga akhir penelitian, dengan menggunakan 10 ekor larva setiap waktu pengambilan sampel. Hasil penelitian menunjukkan bahwa sebagian besar populasi larva telah bermetamorfosis menjadi juvenil pada umur 35 hari. Pada umur tersebut, larva yang diberi penambahan taurin (A) memiliki ukuran yang lebih besar, pertumbuhan yang lebih cepat dan tingkat kelangsungan hidup yang lebih tinggi dibandingkan dengan larva yang tidak diberi penambahan taurin (B). Oleh karenanya, hasil penelitian ini menunjukkan bahwa penambahan taurin pada rotifer dapat meningkatkan pertumbuhan dan kelangsungan hidup larva ikan kerapu bebek.
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Jang, Bok Il, Olumide Samuel Olowe, and Sung Hwoan Cho. "Evaluation of the Optimal Protein Required in Granulated Microdiets for Rockfish (Sebastes schlegeli) Larvae." Aquaculture Nutrition 2022 (August 29, 2022): 1–9. http://dx.doi.org/10.1155/2022/2270384.
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Protein is an essential nutrient that supports fish growth, and the inadequacy in formulating their diets with an optimum protein level can deteriorate their growth performance. The protein requirement in granulated microdiets was estimated for rockfish (Sebastes schlegeli) larvae. Five granulated microdiets (CP42, CP46, CP50, CP54, and CP58) containing 42% to 58% crude protein levels with a 4% increment at a constant gross energy level (18.4 kJ/g diets) were prepared. The formulated microdiets were also compared with imported microdiets, Inve (IV) and love larva (LL) from Belgium and Japan, respectively, and a locally marketed feed (crumble). At the cessation of the study, the survival of larval fish was not different ( P > 0.05 ), but the weight gain (%) of fish fed the CP54, IV, and LL diets was significantly ( P < 0.0001 ) higher than that of larval fish fed the CP58, CP50, CP46, and CP42 diets. The crumble diet achieved the poorest weight gain of larval fish. Furthermore, the total length of rockfish larvae fed the IV and LL diets was significantly ( P < 0.0001 ) longer than that of the fish fed all other diets. The chemical composition of the fish’s whole body, except for ash content, was not influenced by the experimental diets. The experimental diets affected essential amino acid profiles, such as histidine, leucine, and threonine, and nonessential amino acid profiles, such as alanine, glutamic acid, and proline of the whole body of larval fish. Conclusively, based on the broken line analysis of weight gain of larval rockfish, protein requirement in granulated microdiets was estimated to be 54.0%.
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Nastiti, Adriani Sri, Masayu Rahmia Anwar Putri, and Agus Arifin Sentosa. "KOMPOSISI DANKELIMPAHAN LARVAIKAN SEBAGAI DASARPENGELOLAAN SUMBERDAYAIKANDITELUKCEMPI, NUSATENGGARABARAT." BAWAL Widya Riset Perikanan Tangkap 8, no. 3 (January 20, 2017): 137. http://dx.doi.org/10.15578/bawal.8.3.2016.137-146.
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Kawasan pesisir Teluk Cempi sangat penting bagi pemijahan dan perkembangan awal siklus hidup berbagai jenis ikan. Tujuan penelitian ini untuk mendapatkan informasi tentang komposisi, kelimpahan dan sebaran larva ikan di Teluk Cempi, Nusa Tenggara Barat. Penelitian dilakukan pada bulan September 2012 di perairan mangrove Teluk Cempi yang terdiri dari 17 titik sampling, meliputi daerah Jambu, Mbawi, Nowa, Woja dan Lara. Pengambilan sampel larva ikan dilakukan dengan menggunakan simple conical tow-net pada siang (pukul 09.00-16.00) dan malam hari (pukul 19.00-24.00). Hubungan antara kelimpahan larva ikan dengan parameter perairan menggunakan analisis korelasi. Hasil penelitian menunjukkan bahwa pada malam hari, jumlah famili dan kelimpahan larva ikan lebih tinggi (16 famili dengan rataan kelimpahan 471 ekor/1000m3) dibandingkan pada siang hari (14 famili dengan rata kelimpahan 281 ekor/1000m3). Kondisi ini diduga karena larva bersifat nocturnal. Tingginya kelimpahan dan sebaran larva Gobiidae hampir merata di semua stasiun menunjukkan bahwa Gobiidae memiliki toleransi yang tinggi terhadap fluktuasi kondisi lingkungan estuari Teluk Cempi. Suhu merupakan parameter perairan yang mempengaruhi kelimpahan larva ikan saat malam hari, sedangkan salinitas mempengaruhi kelimpahan larva ikan saat siang hari. The larva phase is the susceptible phase in fish cycle. Cempi bay as coastal area in Dompu Regency, West Nusa Tenggara has vital role for fish spawning ground and first life cycle developing. This research aims to assess a difference of composition, abundance and distribution of fish larvae in Cempi Gulf based research period (day and night). The research was conducted on September 2012 in Mangrove waters of Cempi gulf, and collected from 17 point research stations that included Jambu, Mbawi, Nowa, Woja and Lara area. Fish larvae sampled using simple conical tow-net during the day time (09.00 AM – 04.00 PM) and night time (07.00 - 12.00 PM). The relationship between the abundance of larval fish and the water parameters were examined using correlation analysis. In the night time, the family number and larval abundance were higher (16 families and 471 fish/1000m3) than day time (14 families and 281 fish/1000m3). This condition probably due to nocturnal behavior of larvae. Family Gobiidae mostly found in all stations. That condition reflected high tolerance of Gobiidae to the variation of environmental conditions in Cempi bay. Water temperature likely influenced the abundance during night time, while during day time the abundance likely affected by salinity.
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Fraser, Angus J. "Triacylglycerol Content as a Condition Index for Fish, Bivalve, and Crustacean Larvae." Canadian Journal of Fisheries and Aquatic Sciences 46, no. 11 (November 1, 1989): 1868–73. http://dx.doi.org/10.1139/f89-235.
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The lipid biochemistry of environmentally stressed larval fish, bivalves and crustaceans is presented to illustrate the utility of a larval condition index based on lipid composition. Larvae under environmental stress are often unable to obtain sufficient energy from exogenous sources and, as a result, endogenous energy reserves are catabolised to maintain basal metabolism. The storage lipid triacylglycerol (TAG) is of particular importance in this respect, TAG content consequently correlating with the physiological condition of a larva. However, absolute TAG content cannot be directly correlated with larval condition because of its dependency on larval size. It is proposed that TAG content can be correlated with larval condition when expressed in the form of a TAG-sterol ratio that accounts for the size dependency of TAG content. This proposition is supported by data that illustrate a highly positive correlation between sterol content and dry weight for larval herring and larval American lobster. Examples of TAG-sterol ratios are calculated from a survey of studies relating to the lipid class composition of nutritionally and pollutant stressed larvae of some marine fish and crustaceans.
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Dey, Tanwi, Piash Kumer Ghosh, Shishir Kumar Nandi, Gourab Chowdhury, Sohel Mian, and Md Shahab Uddin. "Review on n-3 HUFA and Live Food Organism for Marine Fish Larvae Nutrition." American Journal of Agricultural Science, Engineering, and Technology 6, no. 3 (November 21, 2022): 88–102. http://dx.doi.org/10.54536/ajaset.v6i3.770.
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Marine fish farm industries face ongoing challenges due to a lack of quality seed, a low survival rate and a slow growth rate of marine fish larvae. One of the most sensitive problems is a nutritionally balanced quality feed for rearing these larval fish at the first feeding stage. Many studies have reported high requirements of n-3 highly unsaturated fatty acids, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for proper development, which have also been reported to increase the survival and growth status of larval fish. Marine fish larvae have difficulties accepting artificial feed at their weaning stage, so live food plays a vital role in the rearing process. Artemia is one of the most commonly used live food organisms in marine fish larvae production systems. However, they are deficient in EPA and DHA, which are most critical for larval development. Recent advancements in live food production systems have developed several techniques of bio-encapsulation and enrichment of nutrients in live food. But the instability of DHA and the high cost of enrichment procedures remain-bottlenecks for supplying proper nutrients through live food. This short review emphasizes challenges in marine fish larvae culture in terms of HUFAs nutrition with a comparative study on DHA requirements of marine larval fish and its availability in live food organism Artemia. We also highlighted several factors affecting DHA enrichment process and its degradation following enrichment procedures.
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Staaterman, Erica, and Claire B. Paris. "Modelling larval fish navigation: the way forward." ICES Journal of Marine Science 71, no. 4 (August 24, 2013): 918–24. http://dx.doi.org/10.1093/icesjms/fst103.
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Abstract Recent advances in high-resolution ocean circulation models, coupled with a greater understanding of larval behaviour, have increased the sophistication of individual-based, biophysical models used to study the dispersal of larvae in the sea. Fish larvae, in particular, have the ability to swim directionally and increasingly fast during ontogeny, indicating that they may not only disperse, but also migrate using environmental signals. How and when larvae use local and large-scale cues remains a mystery. Including three-dimensional swimming schemes into biophysical models is becoming essential to address these questions. Here, we highlight state-of-the-art modelling of vertical and horizontal migrations of fish larvae, as well as current challenges in moving towards more realistic larval movements in response to cues. Improved understanding of causes for orientation will provide insight into the evolutionary drivers of dispersal strategies for fish and marine organisms in general.
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Jaxion-Harm, J., and M. R. Speight. "Distribution of fish larvae within a weakly tidal mangrove lagoon." Marine and Freshwater Research 68, no. 2 (2017): 396. http://dx.doi.org/10.1071/mf15292.
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Mangroves have been shown to provide valuable nursery grounds to juvenile fishes, yet little is known regarding larval distribution and settlement processes in this habitat. To investigate fish larvae in mangrove habitat in a semi-isolated lagoon (surface area 750m2), we employed multiple catch methods: plankton tows, minnow traps, and light traps during June–August 2008 and 2009. Overall, nine families of fish larvae were caught in the light traps. Light traps caught significantly more fish larvae during the new moon compared with the full moon. Plankton tow nets caught early-stage, unidentifiable (without DNA analysis) larvae. Minnow traps only caught a total of three fish larvae. Overall, scarids (parrotfish) and lutjanids (snappers) were the most common larvae from coral-reef fish families and were found at sites over 1km upstream of the mouth of the mangrove lagoon. Without the aid of tidal influence (and nets requiring hydrodynamic force), sampling is difficult in these turbid, shallow waters.
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ARAUJO-LIMA, C. A. R. M., V. V. da SILVA, P. PETRY, E. C. OLIVEIRA, and S. M. L. MOURA. "Diel variation of larval fish abundance in the Amazon and Rio Negro." Brazilian Journal of Biology 61, no. 3 (August 2001): 357–62. http://dx.doi.org/10.1590/s1519-69842001000300003.
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Many streams and large rivers present higher ichthyoplankton densities at night. However, in some rivers this does not occur and larvae are equally abundant during the day. Larval drift diel variation is an important information for planning sampling programs for evaluating larval distribution and production. The aim of this study was to test whether the abundance of larval fish was different at either period. We tested it by comparing day and night densities of characiform, clupeiform and siluriform larvae during five years in the Amazon and one year in Rio Negro. We found that larvae of three species of characiform and larvae of siluriform were equally abundant during day and night in the Amazon. Conversely, the catch of Pellona spp. larvae was significantly higher during the day. In Rio Negro, however, larval abundance was higher during the night. These results imply that day samplings estimate adequately the abundance of these characiform and siluriform larvae in the Amazon, but not Pellona larvae. Evaluations of larved densities of Rio Negro will have to consider night sampling.
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DE LIBERATO, CLAUDIO, TERESA BOSSÙ, PAOLA SCARAMOZZINO, GIUSEPPE NICOLINI, PIETRO CEDDIA, SALVATORE MALLOZZI, SERENA CAVALLERO, and STEFANO D'AMELIO. "Presence of Anisakid Larvae in the European Anchovy, Engraulis encrasicolus, Fished Off the Tyrrhenian Coast of Central Italy." Journal of Food Protection 76, no. 9 (September 1, 2013): 1643–48. http://dx.doi.org/10.4315/0362-028x.jfp-13-092.
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A survey was carried out to determine the prevalence of anisakid nematode larvae in European anchovy (Engraulis encrasicolus) fished off the Tyrrhenian coast of central Italy. From February through July 2012, 1,490 specimens of E. encrasicolus caught in three different fishing areas (off Civitavecchia, Anzio, and Gaeta in the northern, central, and southern Lazio region of Italy, respectively) were tested for the presence of anisakid larvae, both by visual microscopic inspection and enzymatic digestion. In each of the three fishing areas, each of two sampling times produced 250 fish (with the exception of one sampling time in Gaeta that produced 240 fish). Larvae of the family Anisakidae were detected with an overall estimated prevalence of 2.3%, and each positive fish harbored a single larva. No anisakid larvae were detected in fish caught off Gaeta. Fish with larvae were significantly longer (standard length) than fish without larvae. Twenty-six larvae (74.3%) were detected by visual inspection of the viscera, eight larvae (22.8%) were detected by visual inspection of the fillets, and one larva (2.8%) was detected after digestion of pooled fillets. Molecular analysis to fully characterize the 35 detected larvae revealed 15 specimens of Anisakis pegreffii, 10 specimens of Hysterothylacium aduncum, and one hybrid genotype of A. pegreffii × Anisakis simplex. For nine specimens, no visible product was obtained after PCR amplification. The overall prevalence for A. pegreffii and H. aduncum was 1.0 and 0.7%, respectively. A comparison between fishes harboring A. pegreffii larvae and those harboring H. aduncum revealed that those with A. pegreffii were significantly heavier. The prevalence of anisakid larvae found in the present study is lower then that reported previously in E. encrasicolus collected in the Mediterranean Sea.
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GIRARD, MATTHEW G., H. JACQUE CARTER, and G. DAVID JOHNSON. "New species of Monomitopus (Ophidiidae) from Hawaiʻi, with the description of a larval coiling behavior." Zootaxa 5330, no. 2 (August 15, 2023): 265–79. http://dx.doi.org/10.11646/zootaxa.5330.2.5.
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In 1985, Carter and Cohen noted that there are several yet-to-be described species of Monomitopus (Ophidiidae), including one from Hawaiʻi. Recently, blackwater divers collected a larval fish off Kona, Hawaiʻi, similar to the previously described larvae of M. kumae, but DNA sequence data from the larva does not match any of the six previously sequenced species within the genus. Within the Smithsonian Institution’s National Museum of Natural History Ichthyology Collection, we find a single unidentified adult specimen of Monomitopus collected North of Maui, Hawaiʻi in 1972 whose fin-ray and vertebral/myomere counts overlap those of the larval specimen. We describe this new Hawaiian species of Monomitopus based on larval and adult characters. Additionally, blackwater photographs of several species of Monomitopus show the larvae coiled into a tight ball, a novel behavior to be observed in cusk-eels. We describe this behavior, highlighting the importance of blackwater photography in advancing our understanding of marine larval fish biology.
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Davenport, John. "Observations on the locomotion of post-larval and juvenile flying fish." Journal of the Marine Biological Association of the United Kingdom 70, no. 2 (May 1990): 311–20. http://dx.doi.org/10.1017/s0025315400035426.
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Post-larval specimens of Hirundichthys affinis are capable of jumping out of water, but the pectoral and pelvic fins are not extended when in air. Penetration through the air/ water interface demands a force to overcome surface tension which is similar in magnitude to the force required for the jump itself. However, post-larvae do not produce the single propulsive tail flick which powers the jump until most of the animal has passed through the interface. The post-larva emerges at an angle close to 45°, thus maximising the horizontal distance travelled before re-entry.Whether swimming slowly (4 body lengths s-1), or at maximum speed (36 body lengths s-1), post-larvae swim with the pectoral and pelvic fins extended. Calculations show that fast swimming post-larvae operate at Reynolds’ numbers of about 4×103, where surface roughness and projections decrease rather than increase drag.
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Sim-Smith, Carina J., Andrew G. Jeffs, and Craig A. Radford. "Variation in the growth of larval and juvenile snapper, Chrysophrys auratus (Sparidae)." Marine and Freshwater Research 63, no. 12 (2012): 1231. http://dx.doi.org/10.1071/mf12176.
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For many fish species, growth and mortality of larvae are closely coupled, with faster-growing larvae generally experiencing higher survivorship in the plankton, which may lead to higher recruitment. Using back-calculated growth trajectories derived from otolith increments we used the modified Fry model to estimate the growth rate of larvae and early juveniles of the commercially important sparid, Chrysophrys auratus, at four sites around northern New Zealand. Back-calculated growth rates were used to test the hypothesis that fish with a short pelagic larval duration (≤20 days) grew faster than did fish with a long pelagic larval duration (>24 days) during both the larval and juvenile periods. At three of the four sites, fish with a short larval duration grew significantly faster during the larval period, and these larvae generally continued to have a larger size-at-age as juveniles up to 70-day-old. Growth rates for both the larval and early juvenile period were also found to vary significantly among the four sites and were found to be unrelated to differences in water temperature. Localised variation in early growth of C. auratus among sites may be important in helping explain differences in their contribution to the recruitment to C. auratus populations.
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Melianawati, Regina, and Bejo Slamet. "Biological Parameters of Blacksaddled Coralgrouper (Plectropomus laevis Lacepède, 1801) Eggs and Larvae." ILMU KELAUTAN: Indonesian Journal of Marine Sciences 24, no. 4 (December 2, 2019): 186. http://dx.doi.org/10.14710/ik.ijms.24.4.186-194.
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Blacksaddled coralgrouper, Plectropomus laevis, is an endangered species of marine fish. As part of conserving their existence in the wild, culture of this species has been started. However, knowledge of biological parameters of this species as important indicators to observe the fish growth in mariculture scale, is limited. The purpose of this study was to observe biological parameters during eggs, larval to juvenile stage of blacksaddled coralgrouper in mariculture hatchery. The eggs were obtained from natural spawning of domesticated broodstocks. Larvae rearing was done in hatchery at three different times as replicates. Larval were fed with zooplankton which consist of rotifers Brachionus sp., wild copepods and Artemia. Artificial feed was also given to the fish larvae. Larval samples were taken one Day After Hatching (DAH), then continued every 5 days started at 5 to 45 DAH by using five larvae each sampling time. The observed parameters were diameter of eggs and oil globule, total length and standard length of larvae length of dorsal and pelvic fin spines of larvae. Furthermore, growth pattern of those length parameters was analysed by regression equation. The result showed that diameter of blacksaddled coralgrouper eggs was 835.19±15.29 µm, while oil globule was 177.78±10.30 µm. The growth patterns of larval total length and standard length were exponential, while dorsal and pelvic fin spines were polynomial. The length of time from larvae to achieve juvenile stage was range between 45-50 days. All of these information can be used as references either in larvae rearing or for further study of the fish.
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Winch, Judith M., and J. Riley. "Studies on the behaviour, and development in fish, ofSubtriquetra subtriquetra: a uniquely free-living pentastomid larva from a crocodilian." Parasitology 93, no. 1 (August 1986): 81–98. http://dx.doi.org/10.1017/s0031182000049842.
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SUMMARYThe primary larva of the porocephalid pentastomidSubtriquetra subtriquetra, which infects the nasopharynx ofCaiman sclerops, is uniquely free-living. Eggs hatch within the nasal passages and the emergent larvae can remain infective to the fish intermediate host for 4–5 days. During this period larvae exhibit very stereotyped behaviour, alternating between a characteristic stationary ‘fishing’ posture and very brief periods of movement. Larval activity increases significantly at 3 days, probably effecting dispersal to a more favourable site for host invasion. Host location is passive and invading larvae penetrate to the swim-bladder where subsequent larval development, which involves 7 moults, occurs. All 8 larval stages are freely mobile in the swim-bladder and possess hooks. Sensilla, disposed in characteristic patterns, are present throughout development, increasing in number to the infective stage; the majority of sensilla are located on sensory papillae.
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Buckwalter, Joseph, Paul L. Angermeier, Jane Argentina, Skylar Wolf, Stephen Floyd, and Eric M. Hallerman. "Drift of Larval Darters (Family Percidae) in the Upper Roanoke River Basin, USA, Characterized Using Phenotypic and DNA Barcoding Markers." Fishes 4, no. 4 (December 8, 2019): 59. http://dx.doi.org/10.3390/fishes4040059.
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Larval fish ecology is poorly characterized because sampling is difficult and tools for phenotypically identifying larvae are poorly developed. While DNA barcoding can help address the latter problem, ‘universal’ primers do not work for all fish species. The Roanoke River in the southeastern United States includes seven darters (Family Percide: Tribe Etheostomatini). We made 393 collections of larval fishes in 2015 and 2018, examined darter larvae for morphometric and pigmentation traits, developed PCR primers amplifying darter DNA, and evaluated three gear types for collecting larval darters. Amplified DNA sequences for 1351 larvae matched archived mitochondrial cytochrome oxidase I sequences for darters occurring in the ecosystem. Larval darters were classified to genus with 100% accuracy using the ratio of pectoral fin length to body length; however, identification to species using morphometrics alone was subject to a misclassification rate of 11.8%, which can be resolved by considering pigmentation patterns. Gear-types varied considerably in their capture efficacy for larval darters; most Percina larvae were collected in drift nets. Larval Percina species appeared in the drift before Etheostoma species in both study years. Application of molecular genetic and phenotypic tools to larval fish identification can advance understanding of larval darter ecology.
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Jude, D. J., P. J. Mansfield, S. F. DeBoe, and F. J. Tesar. "Spatial Distribution of Entrained Fish Larvae in a Power Plant Discharge Canal." Canadian Journal of Fisheries and Aquatic Sciences 43, no. 5 (May 1, 1986): 1070–74. http://dx.doi.org/10.1139/f86-134.
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Larval fish were sampled with plankton nets during June and July at 1-, 3-, and 5-m depths at three stations in the 6-m-deep discharge canal of the Monroe electricity-generating plant on western Lake Erie. Of nine species, gizzard shad (Dorosoma cepedianum) accounted for 96% of all larval fish collected in June and, along with freshwater drum (Aplodinotus grunniens), 78% of those taken in July. Densities of fish larvae at the three depths, and at two of the three stations sampled, were not significantly different. Mean densities of gizzard shad and total fish larvae in June were significantly higher at one station. Fluctuating and significantly lower velocity at that station, causing the flowmeter not to turn while the net was still filtering water, was suspected of causing inflated densities. Generally sizes of larvae were not stratified by depth or station; differences that were found were small. Thus, we concluded that to obtain samples with representative species, densities, and sizes of entrained fish larvae, a stationary net should be positioned where the water has uniform high velocity and is well mixed.
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Dzulhasni, Sahilly, Linuwih Aluh Prastiti, Rio Yusufi Subhan, and Nurul Fatimah. "Analisis Potensi Kelayakan Usaha Budidaya Larva Ikan Discus (Symphysodon sp.)." Jurnal Ilmu-ilmu Perikanan dan Budidaya Perairan 18, no. 2 (December 25, 2023): 161–69. http://dx.doi.org/10.31851/jipbp.v18i2.13058.
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Ikan Discus (Symphysodon sp.) merupakan salah satu komoditi ikan hias air tawar yang memiliki potensi untuk dibudidayakan. Penelitian ini bertujuan untuk mengetahui potensi kelayakan usaha larva ikan Discus dengan fokus pada pengembangan larva ikan menggunakan pakan alami. Metode yang digunakan dalam penelitian ini adalah metode “Deskriptif komparatif”. Berdasarkan hasil analisis ekonomi yang dilakukan mulai dari Asumsi, Total Biaya sebesar Rp. 4.689.667. Hasil Penjualan Per Siklus sebesar Rp. 6.000.000. Laba per siklus sebesar Rp.1.310.333. BEP memperoleh hasil Rp. 3.239.466 dan BEP unit sebanyak 65 Ekor. Berdasarkan analisis usahanya, maka budidaya larva ikan discus dapat dikatakan layak dilakukan dan berpotensi untuk di kembangkan, karena dapat memberikan keuntungan yang baik. Discus fish have developed rapidly among ornamental fish enthusiasts, both on a small scale and in the ornamental fish industry and have a critical point for fish larvae in the form of a transitional phase from the period of care by the parents to the stage of separation from the parents, due to their habit of eating the mucus produced by the parents as the main food for the fish larvae. The nutritional needs of discus fish larvae must be met to support the growth and success of this fish farming by meeting the nutritional needs of fish larvae using natural food. Moina sp. is one of the natural feeds that can be used in the rearing period of discus fish larvae, and it can be improved the quality by enrichment method using HUFA and ascorbic acid because it was the most important nutrient elements in feed which affects growth and survival. The purpose of this study was to determine the combination of doses of Moina sp. natural feed enrichment.
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Erzad, Avisha Fauziah, Sahala Hutabarat, and Max Rudolf Muskananfola. "DISTRIBUSI DAN KELIMPAHAN LARVA IKAN DI KAWASAN PERAIRAN PANTAI DUKUH BEDONO KECAMATAN SAYUNG KABUPATEN DEMAK (Distribution and Abundance of Fish Larvae in Coastal Waters of Bedono Village, Sayung, Demak Regency)." Management of Aquatic Resources Journal (MAQUARES) 6, no. 4 (July 25, 2018): 339–47. http://dx.doi.org/10.14710/marj.v6i4.21322.
Full textAbstract:
Larva ikan merupakan fase kehidupan awal dari pertumbuhan ikan dimana perkembangan organ tubuh belum terbentuk secara sempurna. Distribusi dan kelimpahan larva ikan sangat bergantung pada kondisi perairan di dalamnya. Kawasan perairan pantai merupakan perairan yang terhubung langsung ke laut dan masih dipengaruhi oleh aktivitas daratan. Perairan pantai dukuh Bedono mengalami degradasi akibat berkurangnya tanaman mangrove dan terjadinya rob. Penelitian ini bertujuan untuk mengetahui distribusi dan kelimpahan larva ikan di kawasan perairan pantai dukuh Bedono. Penelitian dilaksanakan pada bulan Maret-April 2017. Metode penelitian yang digunakan adalah survei dengan penentuan titik sampling secara purposive. Hasil yang diperoleh menunjukkan bahwa jumlah larva ikan yang tertangkap sebanyak 2.064 individu terdiri dari 10 famili yakni: Ambassidae (245 ind/100 m3), Mugilidae (507 ind/100 m3), Chanidae (378 ind/100 m3), Engraulidae (288 ind/100 m3), Lutjanidae (73 ind/100 m3), Nemipteridae (109 ind/100 m3), Carangidae (145 ind/100 m3), Gobiidae (160 ind/100 m3), Gerreidae (92 ind/100 m3), dan Oryziatidae (67 ind/100 m3). Larva ikan famili Mugilidae tertangkap paling banyak selama pelaksanaan penelitian. Berdasarkan analisis indeks morisita, pola sebaran larva ikan adalah acak. Kesimpulan yang dapat diperoleh ialah nilai kelimpahan larva ikan tertinggi terdapat pada titik IV sebesar 267 ind/100m3 dan terendah terdapat pada titik III sebesar 185 ind/100 m3. Pola persebaran larva ikan pada semua titik adalah acak dimana semua larva ikan dapat menyesuaikan dan bertahan hidup di mana saja pada suatu ekosistem. Fish larvae are the early life phase of the growth of fish where the development of organs has not been fully formed. The distribution and abundance of fish larvae depend on the condition of the waters in it. Coastal waters are waters that connect directly to the sea and are still influenced by land activities. The coastal waters of Bedono village have degradation due to the decreasing of mangrove plant and the increasing of seawater period. This study aims to determine the distribution and abundance of fish larvae in the coastal region of Bedono village. The research was conducted in March-April 2017. The research method used was a survey with purposive sampling point. The results showed that the number of captured fish larvae of 2,064 individuals consisted of 10 families: Ambassidae (245 ind/100 m3), Mugilidae (507 ind/100 m3), Chanidae (378 ind/100 m3), Engraulidae (288 ind/100 m3) , Lutjanidae (73 ind/100 m3), Nemipteridae (109 ind/100 m3), Carangidae (145 ind/100 m3), Gobiidae (160 ind/100 m3), Gerreidae (92 ind/100 m3), and Oryziatidae (67 ind/100 m3). Fish larvae of the Mugilidae family were caught at the most during the study. Based on the morisita index analysis, the pattern of fish larvae distribution is random. The conclusion that can be obtained is the highest value of fish larvae abundance found at point IV of 267 ind/100 m3 and the lowest is at point III of 185 ind/100 m3. The pattern of the distribution of fish larvae at all points is unevenly where all fish larvae can adapt and survive anywhere in an ecosystem.
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Herjayanto, Muh, Odang Carman, Dinar Tri Soelistyowati, Alimuddin, Aryo Wenang Wicaksono, and Harton Arfah. "The ontogenic study of early life stages of culture-bred Nomorhamphus sp. (Zenarchopteridae) from Lindu, Central Sulawesi." Jurnal Akuakultur Indonesia 22, no. 2 (September 4, 2023): 179–86. http://dx.doi.org/10.19027/jai.22.2.179-186.
Full textAbstract:
Nomorhamphus sp. is a freshwater fish that has been traded as an ornamental fish. This fish is unique as an endemic species with a halfbeak-like jaw and orange color on the caudal fin. However, this fish culture information needs a further information. Based on this condition, it is necessary to conduct a study as a basis for ornamental fish breeding and growing-out activities through domestication. A crucial problem in this fish is larval rearing, which can be observed through ontogeny studies. The study was conducted on the newly-born larval behavior, morphological development, andropodium development, growth, and survival rate at the early stages, namely larvae to juvenile. The results showed that the newly-born larvae of Nomorhamphus sp. Lindu had a total length of 1.6-1.8 cm. Larvae could swim four hours 22 minutes after birth and feed artemia nauplii with surface feeding type. The initial juvenile stage occurred 25 days of post-birth period with a total length of 2.0-2.2 cm. The water condition of the rearing during the study could support the larval transformation to juvenile. This study is the first report related to the aquaculture success of the early life stage of Nomorhamphus sp. Lindu at the domestication stage.
Keywords: andropodium, domestication, endemic halfbeak, larva development, surface feeding
ABSTRAK
Nomorhamphus sp. adalah ikan air tawar yang telah diperdagangkan sebagai ikan hias. Ikan ini memiliki keunikan pada statusnya sebagai spesies endemik, bentuk mulut menyerupai paruh setengah (halfbeak), dan warna oranye pada sirip ekor. Namun informasi budidayanya belum diketahui dengan baik. Karena itu perlu dilakukan kajian sebagai dasar dalam kegiatan pengembangbiakan dan pembesaran sebagai ikan hias melalui domestikasi. Salah satu kegiatan penting dalam budidaya yaitu pemeliharaan larva yang dapat diamati melalui studi ontogeni. Kajian pada studi awal ini dilakukan pada stadia awal hidup yaitu larva sampai juvenil. Pengamatan dilakukan pada tingkah laku larva pascalahir, perkembangan morfologi, perkembangan andropodium, pertumbuhan dan sintasan pada lingkungan budidaya. Hasil penelitian menunjukkan bahwa larva Nomorhamphus sp. Lindu yang baru dilahirkan memiliki panjang total 1,6-1,8 cm. Larva telah dapat berenang pada umur empat jam 22 menit pascalahir (pcl) dan bisa makan naupli artemia dengan tipe surface feeding. Stadia awal juvenil terlihat pada umur 25 hari pcl dengan ukuran panjang total 2,0-2,2 cm. Kondisi media pemeliharaan selama penelitian dapat mendukung kehidupan larva sampai juvenil. Penelitian ini merupakan catatan pertama terkait keberhasilan budidaya stadia awal hidup Nomorhamphus sp. Lindu pada tahap domestikasi.
Kata kunci: andropodium, domestikasi, ikan endemik, tipe makan permukaan, perkembangan larva
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Moo, Chee Yuan, and Hadura Abu Hasan. "Effect of Feeding Rate on Growth Performance and Waste Reduction Efficiency of Black Soldier Fly Larvae (Diptera: Stratiomyidae)." Tropical Life Sciences Research 33, no. 1 (March 31, 2022): 179–99. http://dx.doi.org/10.21315/tlsr2022.33.1.11.
Full textAbstract:
Malaysia like many other developing countries is facing the challenge of poor waste management. This research was conducted to determine the effect of black soldier fly (BSF) in decomposing food waste, palm oil waste, fish waste and yard waste. The development time and waste reduction efficiency of four different organic materials were evaluated. In this study, BSF larvae were fed with all four types of waste at five feeding rates of 0.25, 0.50, 1.00, 1.50 and 2.00 g larva−1 day−1 with three replicates per feeding rate until the larvae reached the pre-pupae stage. During the study, larval development time, larval mortality, pre-pupae weight and waste reduction indexes (WRI) were determined. Food waste and yard waste achieved the highest WRI of 4.43 ± 0.06 and 0.71 ± 0.01, respectively at the feeding rate of 0.50 g larva−1 day−1 while palm oil waste and fish waste attained the highest WRI values at feeding rates of 1.00 g larva−1 day−1 (1.89 ± 0.02) and 0.25 g larva−1 day−1 (3.75 ± 0.24), respectively. The results showed that both variables significantly influenced the bioconversion process, but waste reduction efficiency was the most influential element.
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Munk, Peter. "Larval sand lance (Ammodytes sp.) in the diet of small juvenile wolffish (Anarhichas spp.): predatory interactions in frontal water masses off western Greenland." Canadian Journal of Fisheries and Aquatic Sciences 59, no. 11 (November 1, 2002): 1759–67. http://dx.doi.org/10.1139/f02-147.
Full textAbstract:
The predatory behaviour of two species of juvenile wolffish (Anarhichas lupus and Anarhichas minor) was studied during a field campaign across a frontal area off western Greenland. The study focused on ontogenetic changes in prey-type and -size preference of the wolffish and their predatory impact on a cohabiting population of larval sand lance (Ammodytes sp.). Sampling took place along a cross-shelf transect at latitude 66°20' N, and the analysis is based on stomach contents of assembled wolffish (25 cm in length) and abundance estimates of plankton and fish. An ontogenetic change in wolffish prey preference was evident as a dietary shift from copepods and smaller amphipods to larger amphipods and fish larvae. The inclusion of fish larvae in the wolffish diet led to a marked increase in prey biomass, and fish larvae constituted up to 77% of diet biomass in the largest juveniles caught. Wolffish selectively targeted the smaller-sized part of the larval sand lance population; hence, larval vulnerability increased with decreasing size. Comparison between estimated predation rates and abundances of predator and prey indicated larval predation mortalities of up to 5% per day, with mortality peaking in the vicinity of a hydrographic front. Hence, findings suggest substantial predation pressure on larvae, primarily related to larval size and distribution.
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Garrison, Lance P., William Michaels, Jason S. Link, and Michael J. Fogarty. "Predation risk on larval gadids by pelagic fish in the Georges Bank ecosystem. I. Spatial overlap associated with hydrographic features." Canadian Journal of Fisheries and Aquatic Sciences 57, no. 12 (December 1, 2000): 2455–69. http://dx.doi.org/10.1139/f00-229.
Full textAbstract:
We investigated the relationship between hydrographic variables on Georges Bank and the spatial distribution of larval Atlantic cod (Gadus morhua), larval haddock (Melanogrammus aeglefinus), and two planktivorous fish, Atlantic herring (Clupea harengus) and Atlantic mackerel (Scomber scombrus). We conducted cruises during April-May of 1990, 1994, and 1995 to document spatial distributions and employed logistic regression and a spatial-overlap index to assess relationships between hydrographic variables, spatial distributions and spatial overlap between gadid larvae and planktivorous fish. Cod larvae were more abundant in shallow well-mixed areas, while both haddock larvae and herring were more abundant in stratified areas. Atlantic mackerel occurred in deeper water and had little spatial overlap with the other species. In 1995, the presence of Scotian Shelf water and an intrusion of continental slope water altered temperature and salinity distributions and increased spatial overlap between cod larvae and herring. The stratified areas offer a higher concentration of prey for larval haddock, however there is increased exposure to planktivorous fish predators, creating a potential trade-off between predation and starvation. Due to the high abundance of planktivorous fish and high spatial and temporal overlap, predation is likely an important factor influencing survival of gadid larvae on Georges Bank.
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Rachmawan, Dicky Setya, Norma Afiati, and Niniek Widyorini. "KELIMPAHAN LARVA IKAN SAAT PASANG DAN SURUT DI PERAIRAN SEKTAR LOKASI WISATA BAHARI DUKUH MOROSARI DESA BEDONO, KABUPATEN DEMAK." Management of Aquatic Resources Journal (MAQUARES) 7, no. 1 (December 19, 2018): 59–68. http://dx.doi.org/10.14710/marj.v7i1.22525.
Full textAbstract:
Perairan Morosari merupakan kawasan pesisir yang memiliki dinamika tinggi akibat dari adanya objek wisata bahari, dimana akan berpengaruh pada struktur komunitas sumberdaya perikanan, salah satu diantaranya adalah larva ikan yang ada diperairan tersebut. Larva ikan merupakan fase massa kritis dimulai bagi ikan, dimana pembentukan organ tubuh belum terbentuk secara sempurna. Penelitian ini bertujuan untuk mengetahui jenis dan kelimpahan larva ikan berdasarkan pasang surut yang terdapat di perairan sekitar lokasi wisata bahari Dukuh Morosari Desa Bedono, Kabupaten Demak. Penelitian dilaksanakan pada bulan Juli 2017. Metode penelitian yang digunakan adalah survei dengan penentuan titik sampling secara purposive yang dilakukan di 6 stasiun baik pada saat pasang dan surut. Hasil yang diperoleh menunjukkan bahwa jumlah larva ikan yang tertangkap sebanyak 1156 ind/600m3 terdiri dari 8 famili yakni: Ambassidae (551 ind/600m3), Belonidae (33 ind/600m3), Engraulidae (118 ind/600m3), Gobiidae (8 ind/600m3), Lutjanidae (7 ind/600m3), Mugilidae (130 ind/600m3), Nemipteridae (206 ind/600m3), Oryziatidae (103 ind/600m3). Larva famili Ambassidae merupakan larva yang paling banyak tertangkap, sedangkan larva yang tertangkap dengan jumlah paling sedikit ialah famili Lutjanidae. Hasil uji Independent-Sample T test ialah tidak terdapat perbedaan yang signifikan antara kelimpahan larva ikan saat pasang dan surut pada setiap stasiun maupun setiap pengulangan. Jumlah larva ikan pada saat pasang 613 ind/600m3 dan pada saat surut 543 ind/600m3. Morosari waters are coastal areas that have high dynamics due to the existence of marine tourism object, which will affect the structure of the fishery resources community, one of which is the fish larvae that existed in these waters. Fish larvae is a critical mass phase begun for fish, where the formation of organs has not been fully formed. This study aims to determine the type and fish larvae abundance based on High Tide and Low Tide at Around Waters Marine Tourism Morosari of Bedono Village, Demak. The research was conducted in July 2017. The research method used a survey with purposive sampling conducted at 6 stations both at High Tide and Low Tide. The results showed that the number of fish larvae caught were 1156 ind/600m3 consisting of 8 families: Ambassidae (551 ind/600m3), Belonidae (33 ind/600m3), Engraulidae (118 ind/600m3), Gobiidae (8 ind/600m3), Lutjanidae (7 ind/600m3), Mugilidae (130 ind/600m3), Nemipteridae (206 ind/600m3), Oryziatidae (103 ind/600m3). The family larvae of Ambassidae are most caught larvae, while the larvae caught with the least amount are the Lutjanidae family. The result of the Independent-Sample T test is no significant different between the abundance of fish larvae during tidal and low tide at each station and every repetition. Number of fish larvae at high tide 613 ind / 600m3 and at low tide 543 ind / 600m3.
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Bickerton, Matthew W., Joseph Corleto, Thomas N. Verna, Eric Williges, and Deepak Matadha. "Comparative Efficacy of Pimephales promelas, Fundulus diaphanus, and Gambusia affinis and Influence of Prey Density for Biological Control of Culex pipiens molestus Larvae." Journal of the American Mosquito Control Association 34, no. 2 (June 1, 2018): 99–106. http://dx.doi.org/10.2987/17-6718.1.
Full textAbstract:
ABSTRACT Larval survival times and density-dependent feeding behavior were evaluated with the use of 2 species of fish native to the northeastern USA (Pimephales promelas and Fundulus diaphanus), and the potentially invasive Gambusia affinis. Each species was provided 10, 20, 30, 45, and 60 4th-stage larvae of Culex pipiens molestus/fish in the laboratory and digital images were recorded to quantify the number of surviving larvae at various intervals. Daily feeding rates were greatest at the highest larval density. These were 49.69 ± 4.07 larvae for P. promelas, 60 larvae for F. diaphanus, and 36.44 ± 6.6 larvae for G. affinis. Survival analysis was used to compare efficacy of each fish species over time. All fish species consumed larvae at similar rates at lower densities, but significant differences occurred at densities of 30–60 larvae/fish. Survival times of larvae at the highest density were 44 ± 7.9 h for P. promelas, 15 ± 3.4 h for F. diaphanus, and 70.6 ±13 h for G. affinis. In order to evaluate feeding rate as a function of prey density, we compared consumption rates 1.5 h after feeding with the use of a 4-parameter logistic model. Fundulus diaphanus and G. affinis feeding aligned with the 4-parameter model, indicating that initial feeding rates for these species increased with prey density to an upper limit (satiation). Pimephales promelas feeding within 1.5 h did not align with this model, suggesting that early feeding rates for this species are not heavily influenced by prey density.
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Wolanski, Eric, and Michael J. Kingsford. "Oceanographic and behavioural assumptions in models of the fate of coral and coral reef fish larvae." Journal of The Royal Society Interface 11, no. 98 (September 6, 2014): 20140209. http://dx.doi.org/10.1098/rsif.2014.0209.
Full textAbstract:
A predictive model of the fate of coral reef fish larvae in a reef system is proposed that combines the oceanographic processes of advection and turbulent diffusion with the biological process of horizontal swimming controlled by olfactory and auditory cues within the timescales of larval development. In the model, auditory cues resulted in swimming towards the reefs when within hearing distance of the reef, whereas olfactory cues resulted in the larvae swimming towards the natal reef in open waters by swimming against the concentration gradients in the smell plume emanating from the natal reef. The model suggested that the self-seeding rate may be quite large, at least 20% for the larvae of rapidly developing reef fish species, which contrasted with a self-seeding rate less than 2% for non-swimming coral larvae. The predicted self-recruitment rate of reefs was sensitive to a number of parameters, such as the time at which the fish larvae reach post-flexion, the pelagic larval duration of the larvae, the horizontal turbulent diffusion coefficient in reefal waters and the horizontal swimming behaviour of the fish larvae in response to auditory and olfactory cues, for which better field data are needed. Thus, the model suggested that high self-seeding rates for reef fish are possible, even in areas where the ‘sticky water’ effect is minimal and in the absence of long-term trapping in oceanic fronts and/or large-scale oceanic eddies or filaments that are often argued to facilitate the return of the larvae after long periods of drifting at sea.
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Postner, M., and B. Kramer. "Electrosensory thresholds in larvae of the weakly electric fish Pollimyrus isidori (Mormyridae, Teleostei) during ontogeny." Journal of Experimental Biology 198, no. 3 (March 1, 1995): 783–91. http://dx.doi.org/10.1242/jeb.198.3.783.
Full textAbstract:
Electrosensory thresholds and tuning were determined from behavioural studies in larvae of Pollimyrus isidori using the stop response of their electric organ discharge to weak electrical stimuli. Two age groups were studied: (1) 10- to 15-day-old larvae in which the electric organ discharge (EOD), produced by a distinct larval electric organ, had just stabilized; (2) 54- to 60-day-old larvae, just before the advent of the adult EOD (an adult electric organ functionally replaces that of the larva between about 60 and 80 days). Three stimulus pulse waveforms were used: (1) single-cycle, bipolar sine-wave pulses; (2) single-cycle, monopolar sine-wave pulses and (3) monopolar square-wave pulses. The younger larvae were exceedingly sensitive to weak electrical stimuli, down to the 10 µVp­p cm-1 range. Stimulus pulse duration had a significant effect on threshold for all three pulse waveforms, but the shapes of the tuning curves were quite different. Thresholds at the 'best' pulse duration were lower and the tuning sharper (with a V-shaped curve) with monopolar sine-wave pulses than with bipolar sine-wave pulses. The 'best' pulse duration was 1 ms for both sine-wave pulses, corresponding well to the spectral peak amplitude of larval EODs (964±22 Hz). The threshold curve for monopolar sine-wave pulses appeared to be perfectly adapted for sensing larval rather than adult EODs. With square-pulse stimuli, thresholds increased monotonically with duration and there was no evidence of tuning for this kind of stimulus. These results suggest that both conventional spectral tuning and 'tuning' to a particular pulse waveform (with a monopolar sine-wave pulse best approximating the waveform of a larval discharge) are found in young larvae. In the older age group, larvae were more sensitive to all three kinds of stimuli than those of the younger age group. The sensitivity increase varied from 10 dB to 29 dB; at stimuli of 2.4 µVp­p cm-1, larvae just 18 mm long displayed adult sensitivity. No tuning was seen for square-wave pulses and, as in younger larvae, their effectiveness increased monotonically with duration, so that for neither age group are square-wave pulses a good model for larval EODs. The threshold curves for both types of sine-wave pulse were similar and resembled the broadband tuning curves of Knollenorgan electroreceptors. Tuning was present but weak, with sensitivity for the high-frequency range much greater than for younger larvae. This change is adaptive for sensing both larval and adult EODs and occurred before the larvae developed an adult EOD. The mechanism for a change in tuning that has been established for electroreceptors in adult mormyrids and gymnotiforms, where the spectral properties of the EOD of a fish entrain its electroreceptors, is not found in the larvae of Pollimyrus isidori, which 'anticipate' the tuning necessary for the reception of their own, future adult EOD.