Academic literature on the topic 'Abalones'
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Journal articles on the topic "Abalones"
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Giri, I. Nyoman Adiasmara, Tatam Sutarmat, Hirmawan Tirta Yudha, Ibnu Rusdi, and Bambang Susanto. "GROW-OUT OF ABALONE Haliotis squamata IN FLOATING CAGES FED DIFFERENT PROPORTIONS OF SEAWEED AND WITH REDUCTION OF STOCKING DENSITY." Indonesian Aquaculture Journal 9, no. 1 (June 30, 2014): 15. http://dx.doi.org/10.15578/iaj.9.1.2014.15-21.
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Abalone is a herbivore marine animal which feeds on seaweed. Abalone culture has a good prospect in terms of price, market share and simple culture technique. Thus, a study was conducted with the aim of finding out an effective and efficient abalone culture technique in terms of feed use and density. In this study, a 42 cm diameter plastic container with a 22 cm height was used. Three vertically arranged containers were used as the experimental group which were put into a net box and hung onto a raft so that the containers were placed in a 4 m depth below the sea surface. The juvenile of abalones being used came from a hatchery production that has been adapted to cages environment with Gracilaria sp. and Ulva sp. feed. The initial density of abalones was 450 for each container, with the initial weight of 2.6-3.2 g and the 2.5-2.7 cm shell lengths. The abalones were fed with Gracilaria sp. and Ulva sp. seaweeds with different Gracilaria sp./Ulva sp. proportions, i.e. 100/0% (A); 80/20% (B); and 60/40% (C) as the treatments. Each treatment consisted of two replications. After three months of rearing period, densities of abalones were reduced to be 190 for each experimental unit. Weight and shell length of abalones were measured every month by measuring 25 abalone samples from each experimental unit. The result of the experiment showed that the increase in the Ulva sp. proportion in the feed increased the growth of abalones and decreased the feed conversion. Feeding with Gracilaria sp./Ulva sp. proportion of 60%/40% allowed the best growth of abalones. The decrease of abalone density in the experimental unit after three months of rearing also produced an increase in their growth.
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Wei, Xiaohui, Bingye Yang, Wencui Zeng, Bin Tang, Miaoqin Huang, Xuan Luo, Weiwei You, and Caihuan Ke. "Carotenoid Accumulation in Common and Orange-Muscle Mutant of Abalone, Haliotis gigantea, Fed with Different Macroalgae." Aquaculture Nutrition 2022 (December 30, 2022): 1–10. http://dx.doi.org/10.1155/2022/9287594.
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Aquatic animals cannot synthesize carotenoids, thus they must come from diet or from symbionts. Previous studies have found that orange-muscle abalones are rich in carotenoids, but the effects of different diets on the accumulation of carotenoids are unknown. In this study, the effects of macroalgae (Gracilaria lemaneiformis), fresh and dried kelp (Laminaria japonica) on the contents of the predominant carotenoids, including zeaxanthin, β-carotene, and fucoxanthin, between the common and orange-muscle mutant of Haliotis gigantea were compared through a one-year culture experiment. Our study confirmed that carotenoids in abalones mainly come from diets, and the carotenoid types in the muscles were similar to their diets. We also found that feeding on G.lemaneiformis played an important role in maintaining a stable carotenoid content over time, especially zeaxanthin in H.gigantea. Our data also provided that abalones had a good growth performance under the feeding conditions of G.lemaneiformis. Finally, compared with common abalones, orange-muscle abalones had a notably enhanced ability to accumulate carotenoids through their diet, especially zeaxanthin ( P < 0.01 ). However, the growth performance of orange-muscle abalones was lower than those of common abalones fed the same diets. These results inferred that the content of carotenoid in abalone may be controlled by genetic factors, and diet had a significant influence on the accumulation of carotenoid in abalone to some extent.
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Lee, Hey Gene, MinJoong Joo, Jong-Moon Park, Mi Ae Kim, JeongHun Mok, Seong-Hyeon Cho, Young Chang Sohn, and Hookeun Lee. "Lipid Profiling of Pacific Abalone (Haliotis discus hannai) at Different Developmental Stages Using Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectrometry." Journal of Analytical Methods in Chemistry 2022 (October 17, 2022): 1–12. http://dx.doi.org/10.1155/2022/5822562.
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Pacific abalone (Haliotis discus hannai) is a commercially important mollusk; therefore, improvement of its growth performance and quality has been emphasized. During embryonic development, abalones undergo a series of distinct larval stages, including swimming veliger larvae, juveniles, and mature individuals, and their biomolecular composition varies depending on the developmental stage. Therefore, in the present study, we performed untargeted lipid profiling of abalone tissues at different developmental stages as well as the hemolymph of mature female and male abalones using ultrahigh-performance liquid chromatography-tandem mass spectrometry. These profiles can provide meaningful information to understand compositional changes in lipids through abalone metamorphosis and development. A total of 132 lipids belonging to 15 classes were identified from abalone tissues at different developmental stages. Moreover, 21 lipids belonging to 8 classes were identified from the hemolymph of mature abalones. All data were processed following strict criteria to provide accurate information. Triglycerides and phosphatidylcholines were the major lipid components identified in both tissues and hemolymph, accounting for, respectively, 27% and 15% of all lipids in tissues and, respectively, 24% and 38% of all lipids in the hemolymph. Of note, lysophosphatidylcholine was only detected in the tissues of mature abalones, paving the way for further analyses of abalone lipids based on developmental stages. The present findings offer novel insights into the lipidome of abalone tissues and hemolymph at different developmental stages, building a foundation for improving the efficiency and quality of abalone aquaculture.
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Chen, I.-Wen, Pen-Heng Chang, Min-Shou Chen, Tristan Renault, Meei-Mei Chen, Shu-Ting Kuo, and Chiung-Hsiang Cheng. "EXPLORING THE CHRONIC MORTALITY AFFECTING ABALONES IN TAIWAN: DIFFERENTIATION OF ABALONE HERPESVIRUS-ASSOCIATED ACUTE INFECTION FROM CHRONIC MORTALITY BY PCR AND IN SITU HYBRIDIZATION AND HISTOPATHOLOGY." Taiwan Veterinary Journal 42, no. 01 (March 2016): 1–9. http://dx.doi.org/10.1142/s1682648515500237.
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Abalone herpesvirus (AbHV) infection of cultured abalones Haliotis diversicolor supertexta induced acute high mortality in 2003. Years later, sporadic mortality was noted for an extended period of months, resulting in high cumulative mortality. Moribund abalones were analyzed using PCR, in situ hybridization, and histopathology, because thus far no viral particles have been observed by transmission electron microscopy. PCR using 20 primer sets, specifically designed from sequences of acute AbHV infection, failed to amplify any products from abalones suffering from chronic mortality. Subsequently, a 1406-bp sequence was amplified from chronic moribund abalones, and this sequence showed a 92% (553 bp/602 bp) homology with the gene of an AbHV Taiwan isolate (NCBI serial no. KF537536.1), suggestive of an AbHV pathotype. Histopathology of AbHV pathotype infection showed hemocyte infiltration in the lamina propia of the digestive tract, and hemocytes of various stages were evident, as well as the loss of seminal tubules in the gonad. In situ hybridization revealed that in AbHV infection, positive signals were restricted to the neural ganglia, while in AbHV pathotype infection, positive signals were observed only in the hemocytes. It appeared that the tropism of AbHV shifted from mainly neurotropic in AbHV infection to mainly hemocytotropic in abalone suffering from chronic mortality. Abalone shriveling syndrome-associated virus co-infection was detected in some of AbHV pathotype infection events. Further studies are needed to better understand the pathogenesis of AbHV pathotype affecting H. diversicolor in Taiwan.
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Jwa, Min-Seok, and Chang-Yu Hong. "Prospecting the Effects on Abalone (H. discus) Growth under Low-Salinity Stress after Feeding Citrus Peel (CP) and Ecklonia cava disuse (ECD) as Feed Additives." Journal of Marine Science and Engineering 9, no. 7 (June 26, 2021): 707. http://dx.doi.org/10.3390/jmse9070707.
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This study addressed the effects of adding citrus peel (CP) and Ecklonia cava disuse extract (ECD) in the diet of abalones, which are a highly utilized marine species in Korea. As interest in abalone farming is increasing around the fishing community, the installation of land tanks and fish farms on the southern coast and Jeju Island in South Korea is spreading remarkably. In order to create the best opportunities for survival and reproduction, immunity to disease, and growth potential of abalones, we must consider the diet implemented in abalone farming. The survival rate of abalone has shown positive results when their diet is supplemented with CP and ECD. Our research also concluded that the addition of ECD may have a significant effect on the abalone growth and physiology.
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Kibet, Duncan, and Jong-Ho Shin. "Counting Abalone with High Precision Using YOLOv3 and DeepSORT." Processes 11, no. 8 (August 4, 2023): 2351. http://dx.doi.org/10.3390/pr11082351.
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In this research work, an approach using You Only Look Once version three (YOLOv3)-TensorFlow for abalone detection and Deep Simple Online Real-time Tracking (DeepSORT) for abalone tracking in conveyor belt systems is proposed. The conveyor belt system works in coordination with the cameras used to detect abalones. Considering the computational effectiveness and improved detection algorithms, this proposal is promising compared to the previously proposed methods. Some of these methods have low effectiveness and accuracy, and they provide an incorrect counting rate because some of the abalones tend to entangle, resulting in counting two or more abalones as one. Conducting detection and tracking research is crucial to achieve modern solutions for small- and large-scale fishing industries that enable them to accomplish higher automation, non-invasiveness, and low cost. This study is based on the development and improvement of counting analysis tools for automation in the fishing industry. This enhances agility and generates more income without the cost created by inaccuracy.
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Lin, Hongyue, Yiyang Qian, Jia Chen, Xiaolong Gao, Mo Zhang, Weiwei You, and Rongxin Zhang. "Acoustic Characterization for The Feeding Activities of Haliotis discus Hannai." Applied Sciences 13, no. 9 (April 29, 2023): 5559. http://dx.doi.org/10.3390/app13095559.
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In order to analyze the sound production mechanism and the acoustic characteristics of Haliotis discus hannai during feeding, this paper proposes a multi-source information fusion approach combining passive acoustics with videos. In the experiments, abalones with a shell length of 60 ± 2.7 mm were divided into two groups: Group A was fed with fresh macro algae Gracilaria lemaneiformis as food once each day; Group B was placed on a small amount of sand as impurities at the bottom of the tank. As control groups, Group C did not have abalone or food and Group D did not have abalones but food was added. The eating acoustic signals of abalone were mainly concentrated in the frequency range between 9.49 kHz and 44.36 kHz, wherein the peak frequency is 37.86 ± 2.55 kHz, with the maximum energy −66.43 ± 5.17 dBm/Hz. Each pulse sequence is with a duration of 119.12 ± 70.51 ms and consists of several sub-pulses. Nearly 70% of the pulse sequences consist of 1~2 sub-pulses and the duration of the pulse containing one sub-pulse is 42.62 ± 19.72 ms. The eating rate was kept at 0.61 ± 0.04 times/min at the beginning and was decreased significantly to 0.48 ± 0.08 times/min after 60 min. Note that the characteristic analysis of abalone acoustic signals during feeding are first reported in this manuscript to the best of our knowledge, and this paper also demonstrates that the sound of abalone is produced by scraping and grinding food with radula. Because the eating rate decreases with the reduction in the abalone’s level of hunger, the results may be used as an acoustic indicator of feeding strategy for the abalone aquaculture industry.
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Jwa, Min-seok, and Chang-Yu Hong. "Physiological Responses of Intrinsic Small Abalone Haliotis diversicolor aquatilis under High Temperature Stress by Low Level 60CO Gamma Irradiation-Mediated Hormetic Effect." Journal of Marine Science and Engineering 8, no. 11 (November 12, 2020): 906. http://dx.doi.org/10.3390/jmse8110906.
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Haliotis diversicolor aquatilis (H. diversicolor aquatilis) is one of the aquaculture abalone species in Jeju Island, South Korea. The high water temperature in the middle of the summer season frequently limits the aquaculture productivity of abalone. To cope with the problem, this study aimed to investigate viability, attachment rate, changes of immune response, and physiological properties of juvenile small abalone Haliotis diversicolor aquatilis against high water temperature stress under 60CO-gamma irradiation-mediated hormetic effects. To examine physiological changes of abalone, the gamma-ray irradiated and non-irradiated groups were distinguished by grouping a total of 70 abalones in a treated group and a control group (each group included twenty-five female and ten male abalones). The treated group was exposed to 60CO-gamma irradiation using a designed experimental apparatus, the control group was not. Our results revealed that the low level of gamma ray (20 Gy)-irradiated Haliotis diversicolor aquatilis showed a 100% survival rate during the experiment. After gamma ray exposure, all the abalones were cultured without feeding and bioactivities were measured to examine gamma ray-induced physiological responses. The results suggested the potential for selective breeding using gamma ray irradiation hormesis to manipulate the number of eggs, fertilization rate, hatching rate, and attachment rate. The shell length of juvenile abalone was significantly enhanced by a 20 Gy radiation dose. We could presume that the effect of hormesis in the gamma-ray irradiation parent shellfish also had a genetic effect on the offspring. In order to verify changes in immune response and stress tolerance of abalone under high temperature stress, lysozyme activity and survival rates were compared at a water temperature of 30 °C. Interestingly, the 60Co gamma ray-irradiated abalones exhibited almost a 1.65-fold enhanced survival rate along with reduced lysozyme activity after 12 h of high temperature stress. Our results speculate that low levels of 60Co gamma ray-mediated hormetic effects can be an effective strategy for shell length growth and high temperature stress tolerance.
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Villasante, Alejandro, Natalia Catalán, Rodrigo Rojas, Karin B. Lohrmann, and Jaime Romero. "Microbiota of the Digestive Gland of Red Abalone (Haliotis rufescens) Is Affected by Withering Syndrome." Microorganisms 8, no. 9 (September 13, 2020): 1411. http://dx.doi.org/10.3390/microorganisms8091411.
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Withering syndrome (WS), an infectious disease caused by intracellular bacteria Candidatus Xenohaliotis californiensis, has provoked significant economic losses in abalone aquaculture. The pathogen infects gastroenteric epithelia, including digestive gland, disrupting the digestive system and causing a progressive wilting in abalone. Nonetheless, our knowledge about WS implications in digestive gland microbiota, and its role in diseases progress remains largely unknown. This study aims to determine whether digestive gland-associated microbiota differs between healthy red abalone (Haliotis rufescens) and red abalone affected with WS. Using high-throughput sequencing of the V4 region of the 16S rRNA gene, our results revealed differences in microbiota between groups. Bacterial genera, including Mycoplasma, Lactobacillus, Cocleimonas and Tateyamaria were significantly more abundant in healthy abalones, whilst Candidatus Xenohaliotis californiensis and Marinomonas were more abundant in WS-affected abalones. Whilst Mycoplasma was the dominant genus in the healthy group, Candidatus Xenohaliotis californiensis was dominant in the WS group. However, Candidatus Xenohaliotis californiensis was present in two healthy specimens, and thus the Mycoplasma/Candidatus Xenohaliotis californiensis ratio appears to be more determinant in specimens affected with WS. Further research to elucidate the role of digestive gland microbiota ecology in WS pathogenesis is required.
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Rusdi, Ibnu, Riani Rahmawati, Bambang Susanto, and I. Nyoman Adiasmara. "PEMATANGAN GONAD INDUK ABALON Haliotis squamata MELALUI PENGELOLAAN PAKAN." Jurnal Riset Akuakultur 5, no. 3 (November 28, 2016): 383. http://dx.doi.org/10.15578/jra.5.3.2010.383-391.
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Abalon merupakan hewan yang bersifat herbivora di alam memakan berbagai jenis makroalga. Penelitian ini bertujuan untuk mengetahui pengaruh berbagai makroalga sebagai pakan terhadap perkembangan gonad abalon Haliotis squamata. Dalam penelitian ini diterapkan 4 perlakuan pemberian pakan yaitu: (A) Gracilaria sp., (B) Ulva sp., (C) Sargassum sp., (D) Kombinasi Gracilaria sp. + Ulva sp. + Sargassum sp. (rasio 1:1:1). Rancangan yang digunakan adalah rancangan acak lengkap masing-masing dengan 3 ulangan. Induk-induk abalon dipelihara dalam 12 buah kontainer plastik berlubang ukuran 0,58 m x 0,39 m x 0,31 m dan ditempatkan dalam sebuah bak semen ukuran 3 m x 2 m x 1 m. Setiap kontainer berisi abalon sebanyak 10 ekor dengan ukuran awal rata-rata panjang cangkang dan bobot masing-masing 58,9±1,37 mm dan 36,1±4,06 g. Pakan diberikan dengan dosis 15%-20% dari bobot biomassa setiap 2 hari sekali. Pergantian air menggunakan sistem sirkulasi dengan debit 5-6 L/menit. Hasil penelitian menunjukkan bahwa rata-rata pertumbuhan bobot mutlak dan laju pertumbuhan bobot harian berbeda nyata (P<0,05) antar perlakuan. Tingkat kematangan gonad (TKG) induk abalon pada hari ke-70 diperoleh TKG-III tertinggi dihasilkan pada perlakuan kombinasi Gracilaria + Ulva sp. + Sargassum sp. (P<0,05). Perlakuan pakan kombinasi Gracilaria sp. + Ulva sp. dan Sargassum sp. terlihat lebih sesuai dalam memacu pematangan gonad induk abalon H. squamata. Abalone is a herbivorous animal which consumes various kinds of macroalgae in the wild. The aim of the study was to study the effects of various kinds of macroalgae on gonadal maturation of abalone, Haliotis squamata. The experiment applied four kinds of macroalgae i.e.: (A) Gracilaria sp.; (B) Ulva sp.; (C) Sargassum sp.; and (D) Combination of Gracilaria sp. + Ulva sp. + Sargassum sp. (ratio 1:1:1) as food for abalone broodstock. The experiment was arranged in complete random design with three replications. One cemented tank of 3 m x 2 m x 1 m in size was used for the observation. Twelve plastic containers of 0,58 m x 0,39 m x 0,31 m in size were placed in the tank and stocked with 10 abalones per container with the average size of shell length and body weight were 58.9±1.37 mm and 36.1±4.06 g, respectively. For each treatment, macroalgae was given daily with the dosage between 15% and 20% from the total of body weight. Water exchange was done using flow-through system with rate of exchange of 5-6 L/minute. The result of the study showed that the average of absolute growth and daily growth rate of abalones were significantly different (P<0.05) among treatments. The observation of gonadal development of abalone broodstocks on day-70 revealed that the latest stage III of gonadal maturation was achieved by the broodstock fed with combination treatment of Gracilaria sp. + Ulva sp. + Sargassum sp. (P<0.05). Combination of macroalgae from this treatment was clearly able to stimulate gonadal maturation of H. squamata broodstock.
Dissertations / Theses on the topic "Abalones"
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Jackson, Daniel John. "Applied and molecular approaches to improving the cultivation of the tropical abalone Haliotis asinina Linnaeus /." St. Lucia, Qld, 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17413.pdf.
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Gray, Michael. "Morphometrics and reproduction of Terebrasabella heterouncinata (Polychaeta:Sabellidae), infesting abalone (Haliotis midae) from different culture environments." Thesis, Rhodes University, 2003. http://hdl.handle.net/10962/d1018231.
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In the late 1980's abalone culturalists noticed reduced growth rate and shell deformities in some abalone stocks. These problems were the result of infestations by a shell boring polychaete, Terebrasabella heterouncinata. Under intensive abalone culture conditions the level of infestation can reach epidemic proportions and there are often severe consequences for the host abalone. Heavy sabellid infestation levels have placed the economic viability of several South African farms under threat. This study formed part of an ongoing project that is aimed at investigating the basic biology of Terebrasabella heterouncinata. The majority of abalone farmers in South Africa feed their abalone either naturally occurring kelp (Ecklonia maxima) or the formulated abalone feed, Abfeed. Farmers have suggested that the use of Abfeed is associated with higher sabellid infestation levels and changing the abalone diet from Abfeed to kelp helps reduce sabellid infestation. Speculation has arisen indicating that older, slower growing abalone are more susceptible to sabellid infestation. The effect of host abalone diet history and their growth on sabellid settlement success, morphometries and reproduction was quantified. To better understand the plasticity of the expression of life history traits the variability of morphometric and reproductive characteristics was compared between different farm environments. And more...
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Lambrechts, Daneel. "Molecular analysis of genetic variation and relationships amongst abalone (Haliotis midae) at the I&J abalone hatchery at Danger Point, Gansbaai, R.S.A." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52943.
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Thesis (MSc)--Stellenbosch University, 2002.ENGLISH ABSTRACT: The species Haliotis midae is the only abalone species of commercial importance to the South African fisheries industry. The species is currently under substantial pressure due to commercial harvest and illegal poaching, to the extent that genetic and biodiversity may be under threat. The species is also being cultured in commercial systems for supply to international markets. The South African production for 2002 amounted to 350 tons. The commercial production of abalone may also have implications with regard to genetic diversity of natural and commercial populations. The aim of this project was to assess the genetic diversity of the natural and commercial populations of abalone at the I&J Abalone Farm, Danger Point, Gansbaai, in South Africa, in order to make recommendation with regard to possible impact on natural diversity as well as internal management systems. Distortion of natural genetic diversity or a loss of internal diversity will have detrimental consequences. Representative samples have been obtained from the surrounding natural population, as well as the commercial populations, including the broodstock and various progeny groups. Both mtDNA and AFLP molecular techniques were used to assess genetic diversity. Data analysis showed that the genetic profile of the commercial population display sufficient genetic variation. The genetic structure of the commercial population also displays no significant deviation from that of the surrounding natural population, i.e. the population of origin. The results through give indication of a small, though unsignificant loss of genetic variation from the broodstock to the subsequent progeny groups. The investigation conclude that the commercial populations of abalone at the I&J Abalone Farm, Danger Point, Gansbaai, in its current format holds no threat to the disruption of the genetic diversity of the surrounding natural population. Further, the commercial population possesses sufficient genetic variation in view of future genetic development. There is signs of a slight loss of genetic variation in the change over from the broodstock to the progeny groups. This would necessitate careful and controlled replacement of the original broodstock with new animals from the commercial progeny groups as part of an ongoing process of domestication.
AFRIKAANSE OPSOMMING: Die spesie Haliotis midae is die enigste perlemoen spesie van kommersiële belang vir Suid Afrikaanse visserye. Die spesie verkeer tans onder toenemende druk as gevolg van kommersiële en onwettige vangste, tot so 'n mate dat genetiese en biodiversiteit daardeur geaffekteer kan word. Die spesie word in toenemende mate kunsmatig gekweek vir voorsiening aan internasionale markte. Suid Afrikaanse produksie vir 2002 beloop reeds sowat 350 ton per jaar. Die kunsmatige produksie van perlemoen het ook moontlike implikasies op die genetiese diversiteit van natuurlike en kommersiële populasies van die perlemoen, Haliotis midae. Die doel van die projek was om die aard van genetiese diversiteit van die natuurlike en kommersiële populasies van perlemoen by die I&J Perlemoen Plaas, Danger Point, Gansbaai in Suid Afrika te ondersoek, ten einde aanbevelings te maak ten opsigte van moontlike impak op natuurlike diversiteit asook ten opsigte van interne genetiese bestuurstelsels. Versteuring van natuurlike diversiteit of verlies van interne diversiteit hou nadelige gevolge in. Verteenwoordigende monsters is versamel vanuit die omliggende natuurlike populasies, sowel as van die kommersiële populasie op die plaas, insluitend die teelmateriaal en verskillende nageslaggroepe. Beide mtDNA en AFLP-molekulêre tegnieke is gebruik tydens die ontleding van genetiese diversiteit. Dataontleding het aangetoon dat die genetiese profiel van die kommersiële populasie voldoende genetiese variasie demonstreer. Die genetiese struktuur van die kommersiële populasie toon verder geen betekenisvolle verskil met die omliggende natuurlike populasie nie, dit wil sê met die populasie van oorsprong nie. Die resultate toon verder 'n geringe, dog nie betekenisvolle verlies van genetiese variasie wat waargeneem word met oorgang van die teelmateriaal na die onderskeie nageslaggroepe. Die bevindinge van die ondersoek is dus dat die kommersiële populasie op die I&J Perlemoen Plaas, Danger Point, Gansbaai, in die huidige formaat, geen bedreiging inhou vir die versteuring van die omliggende natuurlike genetiese diversiteit nie. Verdere bevindinge is dat die kommersiële populasie oor voldoende genetiese diversiteit beskik met die oog op toekomstige genetiese ontwikkeling. Daar is tekens van 'n geringe afname in genetiese diversiteit met die oorgang vanaf die teelmateriaal na die nageslaggroepe. Dit beklemtoon die belang van 'n gekontroleerde vervanging van die oorspronklike teelmateriaal met nuwe teeldiere vanuit die kommersiële populasie as deel van die domestikasieproses.
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Britz, P. J. (Peter Jacobus) 1959. "The nutritional requirements of Haliotis midae and development of a practical diet for abalone aquaculture." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005152.
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The available literature on abalone nutrition was synthesised and the prospects for developing a complete pelleted dry feed for Haliotis midae evaluated. The similar body compositions, digestive structures, enzyme activity, acceptance of a wide variety of feed ingredients and comparable growth performance on formulated diets of various abalone species suggests that they have similar nutritional requirements. Abalone also appear to be similar to other farmed monogastric animals in that digestion is primarily extracelluar and they possess a large, muscular crop and stomach. Abalone energy metabolism is carbohydrate based. They are capable of digesting high levels of dietary protein but their ability to utilise fat is limited. Abalone have been shown to consume predictable amounts of dry feed which is efficiently converted into body weight. Efficiency indices of utilisation of formulated feeds, such as feed conversion ratio, protein efficiency ratio, net protein utilisation and apparent digestibility have been successfully applied to abalone. It was concluded that the prospects for developing complete diets for H. midae using a conventional animal feed science model were good. The ability of H. midae to utilise a range of proteins which had potential for inclusion in practical diets was investigated. Five protein rich ingredients, namely, casein, fishmeal, soya oil cake, Spirulina, and torula yeast, were fed to H. midae in semi-purified diets. Two algal diets, fresh Plocamium corallorhiza and dried Ecklonia maxima were fed as controls. Abalone fed on fishmeal and Spirulina based diets displayed significantly higher growth rates than diets containing soya oil cake, torula yeast, casein and E. maxima. Growth rates of abalone fed with P. corallorhiza were significantly lower than all other diets. All artificial diets yield lower feed conversion ratios (0.7-1.8) and higher protein efficiency ratios (3.3-6.5) ratios than the seaweed control diets (FCR = 2.8-3.4; PER = 2.2-3.0). The results indicated that fishmeal and Spirulina were the most suitable proteins for inclusion in practical diets for H. midae. The effect of protein level on growth rate and nutritional indices was evaluated by feeding starch bound, fishmeal based diets containing 27, 32, 37, 42 and 47% protein to juvenile H. midae. Weight gain was positively related to the level of dietary protein, increasing by 18% between 27% and 47% protein. Protein efficiency ratio declining from 3.2 to 2.3 with an increasing dietary protein content. Feed consumption rate was approximately 1% of body weight per day for all diets. Post-weaning abalone (ca. lOmm shell length, 0.2g) differed from larger juveniles (ca. 35mm, 8g) in their response to varying proportions of dietary protein and energy. The smaller animals appeared to have a lower protein requirement and poorer ability to utilise lipid than the larger juveniles. Proximate analyses revealed that the levels of protein, lipid and carbohydrate in abalone soft tissue increased with increasing dietary levels of these nutrients. Larger juveniles contained significantly higher levels of protein and carbohydrate, but lower levels of lipid, ash and moisture, than the smaller post-weaning abalone. The assimilation efficiency of [U-¹⁴C]-arginine by H. midae fed diets enriched with [U-¹⁴C]-arginine was only 0.45%. Furthennore, supplementation of diets with graded levels of crystalline arginine did not have any effect on growth rates. It was concluded that the prospects for defining the quantitative amino acid requirements of H. midae using crystalline amino acids are not promising. Rates of gastric evacuation and enzyme secretion were monitored in juvenile H. midae fed an extruded, fishmeal based dry feed. Gut fullness peaked 6h after feed was offered and the bulk of feed consumed was digested within 24 h. Enzyme secretion appeared to begin with the onset of feeding and continued for at least 6h after peak gut fullness was attained. Protease activity increased significantly following ingestion but amylase activity was maintained at a more or less constant level. A low level of lipase activity was observed suggesting that the ability of H. midae to digest fat is limited. The growth rate of H. midae fed an extruded, fishmeal based feed increased with increasing temperature between 12°C and 20°C. Between 20°C and 24°C a marked decline in growth rate accompanied by a deterioration in feed conversion and increased mortality was observed. Consumption of a dry pelleted feed was shown to be a function of body size and temperature. Based on these data a model which predicts a daily ration for H. midae was developed. The present study showed that H. midae efficiently utilises extruded dry feeds containing conventional feed ingredients. Although technical difficulties were encountered in measuring apparent digestibility, it was concluded that the prospects for developing practical diets according to established nutritional principles are promising.
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Lyon, Robert Gary. "Aspects of the physiology of the South African abalone, Haliotis Midae L., and implications for intensive abalone culture." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005069.
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A physiological study was carried out to determine the effects of temperature, quantity of food fed, feeding activity and size class on the oxygen consumption and ammonia production of the South African abalone Haliotis midae L.. A set of intermittent flow respirometer chambers were used in a recirculating system to measure the oxygen consumption rates of fed (postprandial) and unfed (postabsorptive) abalone for three different size classes (15, 30, and 50mm) at three different temperatures (16°, 20° and 23°C) over a 24 hour period. Ammonia production rates and food consumption rates were simultaneously determined. Oxygen consumption and Ammonia production rates per gram abalone were linear functions of abalone size, temperature, and mass of food consumed. Oxygen consumption and ammonia production rates were found to increase proportionally to temperature and in inverse proportion to abalone size. These rates were significantly higher for fed as opposed to unfed abalone. Equations were derived to predict oxygen consumption and ammonia production for fed and unfed animals for a range of temperatures and size classes of abalone. A 96h LC50 lethal toxicity test for exposure to ammonia established 1.08mg.1⁻¹ of unionised ammonia as the lethal limit. A test on the long term effects on growth of acute exposure (12h) to various sublethal concentrations of ammonia showed no significant effects on growth for concentrations below 0.88 mg.1⁻¹. A safe chronic exposure level of 0.02 mg.1¹ NH₃-N was used to predict optimal flow rates required per kilogram of abalone in a rearing tank over a range of size classes and temperatures. The physiological and biological requirements of H. midae and the implications of this knowledge for rearing tank management and optimal design are discussed.
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Green, Alistair John. "The protein and energy requirements of the South African abalone, Haliotis midae." Thesis, Rhodes University, 2009. http://hdl.handle.net/10962/d1008261.
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The abalone (Haliotis midae) culture industry in South Africa is becoming increasingly dependent on the use of formulated feeds, due to limitations in the supply of kelp. The bulk of the feeds that are currently available were developed based on the requirements of juvenile abalone cultured within the optimal temperature range for growth (18 - 20 °C). However, most abalone farming facilities are land-based pump ashore operations and are thus mostly exposed to temperatures outside of this range. In addition, these feeds have been found to be unsuitable for abalone cultured at elevated water temperatures (> 20°C). The aim of the study was to develop size and temperature specific diets for H midoe through optimisation of dietary protein, energy and lipid levels. Abalone were cultured under farm-like conditions in three partially recirculating temperature controlled systems at either 18, 22 or 24°C and fed formulated diets containing graded levels of protein (18,22 and 26 %) and energy (11.6, 13.5 and 16.2 MJ.kg·I ). Abalone were stocked into baskets at 5 % of available of surface area (n=36) and each diet (n=9) was fed to four baskets of abalone at each of the three temperature regimes for ten weeks. Abalone growth was temperature dependent, with growth declining from 4.33 g.month-I for abalone cultured at 18°C to 0.77 g.month-I at 24°C. Dietary protein could be reduced from 26 to 18 % provided dietary energy levels were maintained at 13.5 MJ.kg- l • A dietary energy level of 11.6 MJ.kg-1 was insufficient to meet the energetic requirements of H midae regardless of the protein content of the diet. The effects of water temperature and body size on the protein requirements of H midae were investigated by culturing abalone at temperatures within the optimal range for abalone farming (i.e. 14, 16 and 18°C). Three size classes of abalone (15, 50 and 80 mm) were fed formulated feed containing graded levels of dietary protein (20, 26, 32, 38 and 44 %) under controlled laboratory conditions for 12 weeks, and, in a separate experiment, under commercial farm conditions for 24 weeks. It was not possible to convincingly define the optimal protein levels for abalone of different sizes in this experiment because growth rates fell below average commercial growth rates obtained on farms. Growth was temperature dependent in the laboratory trial, with the rate of weight gain of the 15 mm (ANOV A: p=0.002) and 50 mm abalone (ANOV A: p=0.02) increasing significantly with an increase in temperature from 14 to 18°C. In the farm trial, dietary protein content did not affect the growth rate of the 10-15 or 80 mm abalone (ANOVA: p>0.05), however, the 50 mm abalone displayed significantly higher weight gain on the 32 % (4.72±0.20 g.month-I ) and 38 % (5.01±0.34 g.month-I ) protein diets compared to those fed the 20 % protein diet (3.75±0.13 g.month-I ) (ANOVA: p=O.OI). Although definition of optimal dietary protein levels were not possible, the effects of dietary protein content and water temperature on the growth of H midae were independent signifying that the protein requirements of abalone are temperature independent. In addition, there was no evidence to indicate that abalone of the different sizes tested here had different dietary protein requirements. The size specific dietary lipid and protein requirements of H midae were investigated by feeding two size classes of abalone (30 and 60 mm initial shell length) diets containing graded levels of dietary lipid (4, 7, 10, 13 and 16 %) and protein (34 - 39 %) for 12 weeks. The 30 and 60 mm abalone were stocked at 7 (n=200) and 9 % (n=36) of the available basket surface area respectively and each diet was fed to four baskets of abalone of each size class. The protein requirements of H. midae are influenced by the amount of available dietary energy and thus it is possible that the ability of abalone to utilise lipids as a source of energy differs in the presence of varying levels of dietary protein. High levels of dietary lipid negatively affected the growth, condition factor and soft tissue glycogen content of both size classes of abalone. This negative effect was greater in the 30 mm size class compared to the 60 mm abalone. The corresponding increase in feed consumption and feed conversion ratio in response to increasing levels of dietary protein also provides evidence that abalone are unable to utilise dietary lipids as an energy source and high levels of dietary lipid probably inhibit the uptake of carbohydrates and protein. High dietary lipid levels did however appear to promote gonad maturation. It was possible to reduce dietary protein from 34 to 20 % without negatively affecting growth through the maintenance of dietary energy levels and thus it is recommended that future experiments on the energy content of formulated feeds should focus on the improved use of carbohydrates. Reductions in the protein portion of formulated feeds for H. midae are possible provided the diet contains sufficient levels of energy supplied from carbohydrates. As the ability of abalone to utilise dietary lipid is limited, lipids are unlikely to play a significant role as an energy source in abalone feeds. Further investigations should focus on the utilisation of various carbohydrate sources in abalone feeds.
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De, Beer Mathilde. "Induction of triploidy in the South African abalone, Haliotis midae, by the use of hydrostatic pressure." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16299.
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Thesis (MSc)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: The indigenous abalone, Haliotis midae has been a successfully cultured aquaculture species in South Africa since 1990. It has a slow growth rate and takes from two to five years to reach market size. Like for most other commercially important abalone species, the slow growth rate of H. midae is a cause of concern with regard to the profitability of farming and global competitiveness of the species. Ploidy manipulation of the maternal genome, a universally growing practice in shellfish culture, is considered a promising method to improve the growth rate of abalone - a desirable trait in aquaculture organisms from a commercial perspective. This manipulation technique is employed to achieve sterility, which results in limited gonad development. The consequent re-allocation of resources to somatic growth results in improved growth. The purpose of this study was to establish a viable method for the induction and validation of triploidy, on a commercial scale, in the South African abalone, H. midae. The focus was on hydrostatic pressure as a method of induction and flow cytometry as the method of validation. The results obtained confirm hydrostatic pressure as an effective method for the induction of triploidy in H. midae, delivering high percentages of triploidy (>80%) over a wide range of pressures and times, in 48 hour-old larvae. Hydrostatic pressure had a negative effect on survival in 20 hour-old larvae. Flow cytometry was validated as a reliable, fast and accurate, though expensive, method for identification of triploidy in H. midae. As an outcome of this study a manual of “Procedures for the Induction and Validation of Triploidy in the abalone” is presented (Appendix 1) together with recommendations for further studies on triploidy in the South African abalone, H. midae.
AFRIKAANSE OPSOMMING: Die inheemse perlemoen, Haliotis midae, is sedert 1990 ‘n suksesvol gekweekte akwakultuur spesie in Suid-Afrika. ‘n Kenmerk van die spesie is die stadige groeitempo van tussen twee en vyf jaar ten einde bemarkbare grootte te bereik. Soos vir die meerderheid perlemoen van kommersiële belang, is hierdie stadige groeitempo rede tot kommer met betrekking tot die winsgewende kweek en wêreldwye mededingendheid van die spesie. Die manipulasie van ploïdie van die moederlike genoom is ‘n toenemende praktyk in skulpvisboerdery en word gereken as ‘n belowende metode om die groeitempo van perlemoen te verbeter. Hierdie manipulasietegniek word gebruik om steriliteit te verkry wat manifesteer as onderdrukte ontwikkeling van die geslagsklier. Die gevolg is die herkanalisering van bronne na somatiese groei. Die doel van hierdie studie was om ‘n lewensvatbare metode vir die induksie van triploïdie op ‘n kommersiële skaal in die Suid-Afrikaanse perlemoen, H. midae, te vestig. Daar is op hidrostatiese druk as metode vir die induksie en vloei-sitometrie as metode vir die geldigverklaring van triploïdie gefokus. Die resultate van hierdie studie bevestig dat hidrostatiese druk ‘n effektiewe metode vir die induksie van triploïdie in H. midae is. Hoë persentasies van triploïdie (>80%) is oor ‘n wye reeks van drukke en tye in 48 uur oue larwes verkry. Daar is gevind dat hidrostatiese drukbehandeling ‘n negatiewe effek op die oorlewing van 20 uur oue larwes het. Vloei-sitometrie is bevestig as ‘n betroubare, vinnig en akkurate, maar duur metode vir die identifikasie van triploïdie in H. midae. As ‘n uitvloeisel van die studie word ‘n handleiding “Procedures for the Induction and Validation of Triploidy in the abalone” (Appendix 1) aangebied tesame met aanbevelings vir verdere studies rakende triploïdie in die Suid-Afrikaanse perlemoen, H. midae.
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Godfrey, Brian Peter. "The potential of abalone stock enhancement in the Eastern Cape Province of South Africa." Thesis, Connect to this title online, 2003. http://eprints.ru.ac.za/23/.
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Swanson, Willie J. "The molecular evolution of abalone fertilization proteins /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9907825.
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Hancock, Andrew. "The biology and fishery of Roe's abalone Haliotis roei Gray in south-western Australia, with emphasis on the Perth fishery /." Connect to this title, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0068.
Full textBooks on the topic "Abalones"
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Awabi bunka to Nipponjin. Tōkyō: Seizandō Shoten, 2000.
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The California abalone industry: A pictorial history. Flagstaff, AZ, USA: Best Pub. Co., 1997.
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National, Abalone Convention (2001 Adelaide S. Aust ). Charting our future: 2001 proceedings, National Abalone Convention, Adelaide, South Australia, 19-21 August 2001. [Adelaide, S. Aust.]: Abalone Industry Association of South Australia, Inc., 2001.
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National Abalone Convention (2001 Adelaide, S. Aust.). Charting our future: Proceedings. [Adelaide, S. Aust.]: Abalone Industry Association of SA Inc., 2001.
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International, Symposium on Abalone Biology Fisheries and Culture (1st 1989 La Paz Baja California Sur Mexico). Schedule & abstracts. La Paz, Baja California Sur, México: El Centro, 1990.
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Fallu, Ric. Abalone farming. Oxford: Fishing News Books, 1990.
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Hone, Patrick William. Abalone hatchery manual for Australia. Williamstown, Vic: South Australian Research and Development Institute, 1997.
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Greef, Kimon De. Poacher: Confessions from the abalone underworld. Cape Town: Kwela Books, 2018.
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All abalone are deaf. 2nd ed. Stewarts Point, Calif: Macias, 1999.
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Kiyotake, Yūji. Awabi to kodai kokka: "Engishiki" ni miru shokuzai no seisan to kanri. Tōkyō: Heibonsha, 2021.
Find full textBook chapters on the topic "Abalones"
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Sawabe, Tomoo. "The Mutual Partnership between Vibrio halioticoli and Abalones." In The Biology of Vibrios, 219–30. Washington, DC, USA: ASM Press, 2014. http://dx.doi.org/10.1128/9781555815714.ch15.
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Koike, Y., A. E. Stott, F. Ahmed, T. Takeuchi, C. Strussman, M. Yokota, S. Segawa, and S. Watanabe. "Trials on New Methods for Seed Culture in Japanese Abalones." In Global Change: Mankind-Marine Environment Interactions, 13–17. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-8630-3_2.
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Yangming, Huang, Gao Jingxian, Tang Guo, Xiong Yanmei, and Min Shungeng. "Identification of Variety and Age of Abalones Based on Near-Infrared Spectroscopy." In Sense the Real Change: Proceedings of the 20th International Conference on Near Infrared Spectroscopy, 118–23. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-4884-8_11.
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Allsopp, Mark, Fabiola Lafarga-De la Cruz, Roberto Flores-Aguilar, and Ellie Watts. "Abalone Culture." In Recent Advances and New Species in Aquaculture, 231–51. Oxford, UK: Wiley-Blackwell, 2011. http://dx.doi.org/10.1002/9781444341775.ch8.
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Tegner, Mia J., and Robert A. Butler. "Abalone Seeding." In Handbook of Culture of Abalone and Other Marine Gastropods, 157–82. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9780429265266-10.
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Koizumi, Yoshikazu, and Youichi Tsuji. "Abalone Haliotis spp." In Application of Recirculating Aquaculture Systems in Japan, 175–211. Tokyo: Springer Japan, 2017. http://dx.doi.org/10.1007/978-4-431-56585-7_8.
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Hahn, Kirk O. "Abalone Aquaculture in California." In Handbook of Culture of Abalone and Other Marine Gastropods, 221–26. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9780429265266-14.
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Hahn, Kirk O. "Larval Development of Abalone." In Handbook of Culture of Abalone and Other Marine Gastropods, 71–100. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9780429265266-6.
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Yoo, Sung Kyoo. "Abalone Farming in Korea." In Handbook of Culture of Abalone and Other Marine Gastropods, 255–64. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9780429265266-17.
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Hahn, Kirk O. "Abalone Aquaculture in Japan." In Handbook of Culture of Abalone and Other Marine Gastropods, 185–94. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9780429265266-12.
Full textConference papers on the topic "Abalones"
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Sahin, Egemen, Can Jozef Saul, Eran Ozsarfati, and Alper Yilmaz. "Abalone Life Phase Classification with Deep Learning." In 2018 5th International Conference on Soft Computing & Machine Intelligence (ISCMI). IEEE, 2018. http://dx.doi.org/10.1109/iscmi.2018.8703232.
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"Assessing alternative management strategies for blacklip abalone." In 19th International Congress on Modelling and Simulation. Modelling and Simulation Society of Australia and New Zealand (MSSANZ), Inc., 2011. http://dx.doi.org/10.36334/modsim.2011.a3.bedford.
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Kaur, Sumandeep, Sahana Chaudhary, Anshul Thakur, Rohit Bajaj, Abhishek Gupta, and Anshuman Majotra. "Abalone Age Prediction using Optimized Ensembel Model." In 2022 11th International Conference on System Modeling & Advancement in Research Trends (SMART). IEEE, 2022. http://dx.doi.org/10.1109/smart55829.2022.10047096.
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Bell, L., T. White, M. Donnellan, K. Hebert, and P. Raimondi. "Monitoring Pinto Abalone Populations and Recruitment in Sitka Sound, Alaska." In Monitoring Pinto Abalone Populations and Recruitment in Sitka Sound, Alaska, edited by F. J. Mueter, M. R. Baker, S. C. Dressel, and A. B. Hollowed. Alaska Sea Grant, University of Alaska Fairbanks, 2018. http://dx.doi.org/10.4027/icedhlff.2018.04.
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Ye, Mingguo, and Juan Li. "Abalone counting based on improved Faster R-CNN." In BIC 2022: 2022 2nd International Conference on Bioinformatics and Intelligent Computing. New York, NY, USA: ACM, 2022. http://dx.doi.org/10.1145/3523286.3524542.
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Misman, Muhammad Faiz, Azurah A. Samah, Nur Azni Ab Aziz, Hairudin Abdul Majid, Zuraini Ali Shah, Haslina Hashim, and Muhamad Farhin Harun. "Prediction of Abalone Age Using Regression-Based Neural Network." In 2019 1st International Conference on Artificial Intelligence and Data Sciences (AiDAS). IEEE, 2019. http://dx.doi.org/10.1109/aidas47888.2019.8970983.
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Han, Chang-Wook. "Predicting the Age of Abalone using Morphological Neural Networks." In Smart Technologies in Data Science and Communication 2017. Science & Engineering Research Support soCiety, 2017. http://dx.doi.org/10.14257/astl.2017.147.11.
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Susanto, Marliadi, Mamika Ujianita Romdhini, Siti Raudhatul Kamali, and Laya Zurfani. "Logistic model of abalon’s length growth in Sekotong, West Lombok." In PROCEEDINGS OF THE 2ND INTERNATIONAL CONFERENCE ON BIOSCIENCE, BIOTECHNOLOGY, AND BIOMETRICS 2019. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5141285.
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Papadopoulos, Athanasios, Konstantinos Toumpas, Antonios Chrysopoulos, and Pericles A. Mitkas. "Exploring optimization strategies in board game Abalone for Alpha-Beta search." In 2012 IEEE Conference on Computational Intelligence and Games (CIG). IEEE, 2012. http://dx.doi.org/10.1109/cig.2012.6374139.
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Bassett, Christine, C. Fred T. Andrus, and C. Fred T. Andrus. "ABALONE: A NEW TOOL FOR UNDERSTANDING UPWELLING IN THE CALIFORNIA CURRENT." In GSA Connects 2021 in Portland, Oregon. Geological Society of America, 2021. http://dx.doi.org/10.1130/abs/2021am-370258.
Full textReports on the topic "Abalones"
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Lenihan, Hunter S. Assessing Withering Syndrome Resistance in California Black Abalone: Implications for Conservation and Restoration. Fort Belvoir, VA: Defense Technical Information Center, January 2009. http://dx.doi.org/10.21236/ada514157.
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Shpigel, Muki, Allen Place, William Koven, Oded (Odi) Zmora, Sheenan Harpaz, and Mordechai Harel. Development of Sodium Alginate Encapsulation of Diatom Concentrates as a Nutrient Delivery System to Enhance Growth and Survival of Post-Larvae Abalone. United States Department of Agriculture, September 2001. http://dx.doi.org/10.32747/2001.7586480.bard.
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The major bottlenecks in rearing the highly priced gastropod abalone (Haliotis spp.) are the slow growth rate and the high mortality during the first 8 to 12 weeks following metamorphosis and settling. The most likely reason flor these problems is related to nutritional deficiencies in the diatom diet on which the post larvae (PL) feed almost exclusively in captivity. Higher survival and improved growth rate will reduce the considerable expense of hatchery-nursery resisdence time and thereflore the production costs. BARD supported our research for one year only and the support was given to us in order to prove that "(1) Abalone PL feed on encapsulated diatoms, and (2) heterotrophic diatoms can be mass produced." In the course of this year we have developed a novel nutrient delivery system specifically designed to enhance growth and survival of post-larval abalone. This approach is based on the sodium-alginate encapsulation of heterotrophically grown diatoms or diatom extracts, including appetite-stimulating factors. Diatom species that attract the PL and promote the highest growth and survival have been identified. These were also tested by incorporating them (either intact cells or as cell extracts) into a sodium-alginate matrix while comparing the growth to that achieved when using diatoms (singel sp. or as a mixture). A number of potential chemoattractants to act as appetite-stimulating factors for abalone PL have been tested. Preliminary results show that the incorporation of the amino acid methionine at a level of 10-3M to the sodim alginate matrix leads to a marked enhancement of growth. The results ol these studies provided basic knowledge on the growth of abalone and showed that it is possible to obtain, on a regular basis, survival rates exceeding 10% for this stage. Prior to this study the survival rates ranged between 2-4%, less than half of the values achieved today. Several diatom species originated from the National Center for Mariculture (Nitzchia laevis, Navicula lenzi, Amphora T3, and Navicula tennerima) and Cylindrotheca fusiformis (2083, 2084, 2085, 2086 and 2087 UTEX strains, Austin TX) were tested for heterotrophic growth. Axenic colonies were initially obtained and following intensive selection cycles and mutagenesis treatments, Amphora T3, Navicula tennerima and Cylindrotheca fusiformis (2083 UTEX strain) were capable of growing under heterotrophic conditions and to sustain highly enriched mediums. A highly efficient selection procedure as well as cost effective matrix of media components were developed and optimized. Glucose was identified as the best carbon source for all diatom strains. Doubling times ranging from 20-40 h were observed, and stable heterotroph cultures at a densities range of 103-104 were achieved. Although current growth rates are not yet sufficient for full economical fermentation, we estimate that further selections and mutagenesis treatments cycles should result in much faster growing colonies suitable for a fermentor scale-up. As rightfully pointed out by one of the reviewers, "There would be no point in assessing the optimum levels of dietary inclusions into micro-capsules, if the post-larvae cannot be induced to consume those capsules in the first place." We believe that the results of the first year of research provide a foundationfor the continuation of this research following the objectives put forth in the original proposal. Future work should concentrate on the optimization of incorporation of intact cells and cell extracts of the developed heterotrophic strains in the alginate matrix, as well as improving this delivery system by including liposomes and chemoattractants to ensure food consumption and enhanced growth.
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Whitaker, Stephen. Rocky intertidal community monitoring at Channel Islands National Park: 2018–19 annual report. National Park Service, August 2023. http://dx.doi.org/10.36967/2299674.
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Channel Islands National Park includes the five northern islands off the coast of southern California (San Miguel, Santa Rosa, Santa Cruz, Anacapa, and Santa Barbara Islands) and the surrounding waters out one nautical mile. There are approximately 176 miles of coastline around the islands, about 80% of which is composed of rock. The diversity and undisturbed nature of the tidepools of this rocky coastline were recognized as special features of the islands in the enabling legislation. To conserve these communities unimpaired for future generations, the National Park Service has been monitoring the rocky intertidal communities at the islands since 1982. Sites were established between 1982 and 1998. Site selection considered visitation, accessibility, presence of representative organisms, wildlife disturbance, and safety. This report summarizes the 2018–2019 sampling year efforts (from November 2018 to April 2019) and findings of the Channel Islands National Park Rocky Intertidal Community Monitoring Program. Specific monitoring objectives are 1) to determine the long-term trends in percent cover of key sessile organisms in the rocky intertidal ecosystem, and 2) to determine population dynamics of black abalone (Haliotis cracherodii), owl limpets (Lottia gigantea), and ochre sea stars (Pisaster ochraceus). Objectives were met by monitoring percent cover of core species in target intertidal zones using photoplots and transects, and by measuring size frequency and abundance of black abalone, owl limpets, and sea stars using fixed plots or timed searches. Twelve key species or assemblages, as well as the substrate, tar, have been monitored twice per year at 21 sites on the five park islands as part of the rocky intertidal community monitoring program. Fixed photoplots were used to monitor the percent cover of thatched and acorn barnacles (Tetraclita rubescens, Balanus glandula/Chthamalus spp., respectively), mussels (Mytilus californianus), rockweeds (Silvetia compressa, and Pelvetiopsis californica (formerly Hesperophycus californicus), turfweed (Endocladia muricata), goose barnacles (Pollicipes polymerus) and tar. Point-intercept transects were used to determine the percent cover of surfgrass (Phyllospadix spp.). Information about size distribution (i.e., “size frequency” data) was collected for owl limpets in circular plots. Size distribution and relative abundance of black abalone and ochre sea stars were determined using timed searches. The maximum number of shorebirds and pinnipeds seen at one time were counted at each site. The number of concession boat visitors to the Anacapa tidepools was collected and reported. All sites were monitored in 2018–2019. This was the third year that we officially reduced our sampling interval from twice per year (spring and fall) to once in order to streamline the program and allow for the implementation of additional protocols. Weather conditions during the site visits were satisfactory, but high wind coupled with strong swell and surge limited or prevented the completion of some of the abalone and sea star searches. The percent cover for most key species or assemblages targeted in the photoplots was highly variable among sites. Mussel (Mytilus californianus) cover remained below average at Anacapa and Santa Barbara Islands. Record or near record low abundances for Mytilus were measured at Middle West Anacapa (Anacapa Island), Harris Point (San Miguel Island), Prisoner’s Harbor (Santa Cruz Island), and Sea Lion Rookery (Santa Barbara Island) sites. The only site that appeared to have above average Mytilus cover was Scorpion Rock on Santa Cruz Island. All other sites had mussel cover near or below the long-term mean. Qualitatively, Mytilus recruitment appeared low at most sites. Both rockweed species, Silvetia compressa and Pelvetiopsis californica (formerly Hesperophycus californicus), continued to decrease markedly in abundance this year at the majority of sites compared to combined averages for previous years. Fossil Reef and Northwest-Talcott on Santa Rosa Island, Sea Lion Rookery on Santa Barbara Island, and South Frenchy’s Cove on Anacapa Island were the only sites that supported Silvetia cover that was near the long-term mean. No sites exhibited above average cover of rockweed. Extremely high levels of recruitment for Silvetia and Pelvetiopsis were documented at many sites. Most sites exhibited marked declines in S. compressa abundances beginning in the early 2000s, with little recovery observed for the rockweed through this year. Barnacle (Chthamalus/Balanus spp.) cover fell below the long-term means at all islands except Anacapa, where barnacle cover was slightly above average. Endocladia muricata abundances remained comparable to the grand mean calculated for previous years at Santa Barbara, Santa Cruz, and Santa Rosa Islands, while cover of the alga decreased slightly below the long-term means at Anacapa and San Miguel Islands. Black abalone (Haliotis cracherodii) abundances at the islands remain less than one percent of 1985 population levels. Zero abalone were found throughout the entire site at Landing Cove on Santa Barbara Island and South Frenchy’s Cove on Anacapa Island. Above average abundances relative to the long-term mean generated from post-1995 data were observed at all but five sites. Juvenile black abalone were seen at all islands except Santa Barbara. Ochre sea star (Pisaster ochraceus) populations crashed in 2014 at all monitoring sites due to Sea Star Wasting Syndrome, an illness characterized by a suite of symptoms that generally result in death. The mortality event was widely considered to be the largest mortality event for marine diseases ever seen. Beginning in June 2013, the disease swiftly and significantly impacted P. ochraceus (among other species of sea stars) populations along the North American Pacific coast from Alaska to Baja California, Mexico. By the beginning of 2014, P. ochraceus abundances had declined by >95% at nearly all Channel Islands long-term intertidal monitoring sites, in addition to numerous other locations along the West Coast. At various times during the past decade, extremely high abundances (~ 500 P. ochraceus) have been observed at multiple sites, and most locations have supported >100 sea stars counted during 30-minute site-wide searches. This year, abundances ranged 0–13 individuals per site with all but one site having fewer than 10 P. ochraceus seen during routine searches. Insufficient numbers of sea stars were seen to accurately estimate the size structure of P. ochraceus populations. Only two juveniles (i.e., <50 mm) were observed at all sites combined. Giant owl limpet densities in 2018–2019 were comparable or slightly above the long-term mean at seven sites. Exceptionally high densities were measured at Northwest-Talcott on Santa Rosa Island, Otter Harbor on San Miguel Island, and Willows Anchorage on Santa Cruz Island. The sizes of L. gigantea this year varied among sites and islands. The smallest L. gigantea were observed at Otter Harbor followed closely by Willows Anchorage and Anacapa Middle West, and the largest were seen at Northwest-Talcott. Temporally, the mean sizes of L. gigantea in 2018–2019 decreased below the long-term mean at each island except Anacapa. Surfgrasses (Phyllospadix spp.) are typically monitored biannually at two sites each on Santa Cruz and Santa Rosa Islands. Beginning in 2015, all transects at each of the monitoring sites were only sampled once per year. At East Point on Santa Rosa Island, the conditions were not conducive to sampling the surfgrass transects, but qualitatively, percent cover of surfgrass appeared to be near 100% on all three transects. Relative to past years, cover of surfgrass increased above the long-term mean at Fraser Cove on Santa Cruz Island, fell slightly below the mean at Trailer on Santa Cruz Island, and remained approximately equivalent to the mean at the two Santa Rosa Island sites. Overall, the abundance and diversity of shorebirds in 2018–2019 at all sites appeared similar to observations made in recent years, with the exception of elevated numbers of brown pelicans (Pelecanus occidentalis) observed at East Point on Santa Rosa Island. Black oystercatchers (Haematopus bachmani) were the most ubiquitous shorebird seen at all sites. Black turnstones (Arenaria melanocephala) were not common relative to past years. Pinniped abundances remained comparable in 2018–2019 to historical counts for all three species that are commonly seen at the islands. Harbor seals (Phoca vitulina) were seen in the vicinity of eight sites this year. As in past years, harbor seals were most abundant at Otter Harbor and Harris Point on San Miguel Island. Elephant seals (Mirounga angustirostris) were seen at six sites during the year, where abundances ranged 1–5 individuals per location. California sea lions (Zalophus californianus) were common at Santa Barbara Island; 117 individuals were observed at Sea Lion Rookery. Sea lion abundances were higher than usual at Harris Point (N = 160) and Otter Harbor (N = 82) on San Miguel Island. Relative to past years, abundances this year were considered average at other locations.