Статті в журналах: "Claspers"

1

López-Jofré, Álvaro, Sebastián Hernández, and Héctor Flores. "Description of the dermal denticles on pre-pelvic claspers of the Cockfish, Callorhinchus callorynchus (Holocephali: Callorhinchidae), from Coquimbo, Chile." Revista de Biología Marina y Oceanografía 58, no. 3 (December 31, 2023): 186–93. http://dx.doi.org/10.22370/rbmo.2023.58.3.4279.

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Chimaeras or Ghost sharks (Subclass Holocepahli) have sexual structures called pre-pelvic claspers, and these structures are covered by dermal denticles. In this study, dermal denticles present in pre-pelvic claspers of the Cockfish, Callorhinchus callorynchus, were described in order to compare them with those of other known species of this subclass. Pre-pelvic claspers of 22 specimens were removed for further examination. Dermal denticles on the flat surface of pre-pelvic claspers were different when examining their size, shape, and number of cusps. Dermal denticles were classified as type A (three cusps), B (four cusps), C (five cusps), D (six cusps) and E (eight cusps). Dermal denticles with fewer cusps were located near the center, whereas those with more cusps were located towards the periphery. All types of dermal denticles were found in the largest individuals (> 40 cm length). Possible functions of the dermal denticles and the pre-pelvic clasper in the reproductive activity of this species are suggested.

2

Ritter, EK, and LVJ Compagno. "Clasper Flaring: Maintenance Behavior, or a Normally Hidden Feature of Male Whitetip Reef Sharks, Triaenodon Obesus?" Open Fish Science Journal 6, no. 1 (March 8, 2013): 10–12. http://dx.doi.org/10.2174/1874401x01306010010.

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Male whitetip reef sharks, Triaenodon obsesus, are able to pivot their claspers beyond regular flexing, including spreading their distal tips in a funnel like fashion. The feature of this extended clasper flexing, labelled clasper flaring, is described here. It is speculated to possibly reflect a pre- or post-copulation-related behavior.

3

Sephid, Hesam, Negin Salamat, and Mohammad Ali Salari. "Sexual development and maturity of the male brown banded bamboo shark, Chiloscyllium punctatum (Elasmobranchii : Hemiscylliidae)." Marine and Freshwater Research 72, no. 8 (2021): 1160. http://dx.doi.org/10.1071/mf20305.

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The present study aimed to assess the reproductive biology of male brown banded bamboo shark (Chiloscyllium punctatum). Morphological and histological changes in the reproductive tract and changes in gonad steroid testosterone were assessed in 110 male C. punctatum collected from Bahrakan Creek between January 2018 and March 2019. The reproductive tract in male C. punctatum consisted of a pair of testes, efferent ducts, epididymidis, ductus deferens, seminal vesicles, Leydig gland and claspers. Four sexual development stages were determined: (1) immature, no calcified claspers (2) maturing, partially calcified claspers; (3) active and resting adults. Both adult resting and active stages had calcified claspers. In this study, immature male C. punctatum without calcified claspers were found from August to October, maturing C. punctatum with partially calcified claspers were found from November to January and adult C. punctatum caught from February to April were active with calcified claspers, whereas adult fish collected from May to July and during the rest of the year (until mid-January in the following year) were in the resting stage with inactive testes. The testis had a lobular structure and the spermatocysts were arranged diametrically (i.e. along the cross-sectional width of the testis) in each lobule. Plasma testosterone concentrations were associated with histomorphological changes in the reproductive tract. Testosterone concentrations peaked in March in active males and then decreased significantly in resting males. Overall, the variations in the reproductive organs during different sexual maturity stages were consistent with their roles in the production, movement and release of spermatozoa.

4

Dharmadi, Dharmadi. "ASPEK BIOLOGI IKAN PARI BLENTIK (Dasyatis cf. kuhlii) YANG TERTANGKAP DI LAUT JAWA." Jurnal Penelitian Perikanan Indonesia 14, no. 4 (February 8, 2017): 363. http://dx.doi.org/10.15578/jppi.14.4.2008.363-370.

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Penelitian dilakukan pada tahun 2002 sampai dengan 2003 di tempat pendaratan ikan Muara Angke dan Laboratorium Balai Riset Perikanan Laut Muara Baru, Jakarta. Data aspek biologi reproduksi ikan pari blentik (Dasyatis cf. kuhlii), berasal dari hasil tangkapan sampingan dari alat tangkap jaring dasar yang beroperasi di Laut Jawa dan didaratkan di tempat pendaratan ikan Muara Angke. Hasil penelitian menunjukkan ukuran lebar tubuh ikan pari blentik (Dasyatis cf. kuhlii) terkecil antara 170 sampai dengan 190 mm dan ukuran terbesar antara 330 sampai dengan 350 mm. Hubungan antara lebar cawan dan panjang klasper ikan pari blentik (Dasyatis cf. kuhlii) menunjukan hubungan yang linier (R2=0,7629). Kondisi klasper belum terjadi pengapuran atau sebagian mengandung zat kapur (non or partially calcified claspers) terdapat pada ukuran lebar tubuh <200 mm, sedangkan kondisi klasper penuh zat kapur (fully calcified claspers) terdapat pada ukuran lebar tubuh >250 mm. Ukuran embrio terkecil dijumpai pada bulan Januari yaitu antara 25 sampai dengan 30 mm dan terbesar antara 110 sampai dengan 115 pada bulan Agustus. Sebagian besar ikan pari blentik (Dasyatis cf. kuhlii) jantan yang tertangkap di Laut Jawa dalam kondisi matang kelamin. Berdasarkan pada uji X2, perbandingan kelamin jantan dan betina berbeda nyata (P<0,1). This study was conducted at Muara Angke fish landing site and Research Institute for Marine Fisheries Laboratory Muara Baru Jakarta on 2002 to 2003. Reproduction biology data of Dasyatis cf. kuhlii were taken from catched of bottom net fishing gear that operated in the Java Sea. The result showed that the smallest and the biggest of Dasyatis cf. kuhlii ranging from 170 to 190 mm and 330 to 350 mm disc width, respectively. Relationship between clasper length and disc width was linier (R2=0.7629). Condition of sex maturity stage of male was non or partially calcified claspers found at size <200 mm Wd, while fully calcified claspers was found at size >250 mm Wd. The smallest size embryo of ranging from 25 to 30 mm was found in January and the biggest ranging from 110 to 115 mm was found from in August. Most of Dasyatis cf. kuhlii caught in the Java Sea were mature. Sex ratio was significant different between male and female (X2 test, P<0.1).

5

Hagen, Joanna F. D., Cláudia C. Mendes, Amber Blogg, Alexander Payne, Kentaro M. Tanaka, Pedro Gaspar, Javier Figueras Jimenez, Maike Kittelmann, Alistair P. McGregor, and Maria D. S. Nunes. "tartan underlies the evolution of Drosophila male genital morphology." Proceedings of the National Academy of Sciences 116, no. 38 (September 4, 2019): 19025–30. http://dx.doi.org/10.1073/pnas.1909829116.

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Male genital structures are among the most rapidly evolving morphological traits and are often the only features that can distinguish closely related species. This process is thought to be driven by sexual selection and may reinforce species separation. However, while the genetic bases of many phenotypic differences have been identified, we still lack knowledge about the genes underlying evolutionary differences in male genital organs and organ size more generally. The claspers (surstyli) are periphallic structures that play an important role in copulation in insects. Here, we show that divergence in clasper size and bristle number between Drosophila mauritiana and Drosophila simulans is caused by evolutionary changes in tartan (trn), which encodes a transmembrane leucine-rich repeat domain protein that mediates cell–cell interactions and affinity. There are no fixed amino acid differences in trn between D. mauritiana and D. simulans, but differences in the expression of this gene in developing genitalia suggest that cis-regulatory changes in trn underlie the evolution of clasper morphology in these species. Finally, analyses of reciprocal hemizygotes that are genetically identical, except for the species from which the functional allele of trn originates, determined that the trn allele of D. mauritiana specifies larger claspers with more bristles than the allele of D. simulans. Therefore, we have identified a gene underlying evolutionary change in the size of a male genital organ, which will help to better understand not only the rapid diversification of these structures, but also the regulation and evolution of organ size more broadly.

6

Jones, Ashlee A., Norman G. Hall, and Ian C. Potter. "Size compositions and reproductive biology of an important bycatch shark species (Heterodontus portusjacksoni) in south-western Australian waters." Journal of the Marine Biological Association of the United Kingdom 88, no. 1 (February 2008): 189–97. http://dx.doi.org/10.1017/s0025315408000209.

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Heterodontus portusjacksoniwas obtained from the catches of commercial trawl, gillnet and longline fisheries operating in south-western Australian waters, in which this shark is an abundant bycatch species. Ninety per cent of theH. portusjacksonicaught by commercial trawling in a marine embayment were <400 mm in total length, whereas 99 and 100%, respectively, of the individuals taken by commercial gillnet and longline outside that embayment were >400 mm. Although the differences between the size compositions in the catches obtained by trawling vs both gillnetting and longlining, which were similar, are partly attributable to gear selectivity, they also reflect a use by juvenileH. portusjacksoniof protected nearshore waters as nursery areas and a tendency for larger juveniles and adults to occupy reef/rock habitats in a range of water depths. The fact that all but one of the numerousH. portusjacksoni>800 mm were females is reflected in the ratio of females to males differing significantly from parity in the gillnet and longline samples. Yolked oocytes usually take one year to develop to ovulatory size. Ovulation occurs in late winter to early summer and hatching takes place a year later when the embryo is 180–220 mm. The claspers of males commence rapid growth at a total length of ~450 mm, coincident with the onset of clasper calcification and gonadal maturation. The rate of clasper growth relative to total length reached a maximum at ~570 mm and then declined precipitously as the claspers approached full calcification. Based on gonadal criteria, theL50at maturity for females (805 mm) was nearly 40% greater than that for males (593 mm). Values of the deviance information criterion and marked overlap in their 95% confidence intervals demonstrate that theL50of 581 mm derived for males using full clasper calcification as the index of maturity was equally valid as the aboveL50derived for males at maturity using gonadal criteria. The capture of substantial numbers of juveniles by trawling and of females <L50at maturity by gillnetting and longlining may be having localized effects on the population structure ofH. portusjacksoniin south-western Australian waters.

7

CONANT, J. "ON A THEOREM OF GOUSSAROV." Journal of Knot Theory and Its Ramifications 12, no. 01 (February 2003): 47–52. http://dx.doi.org/10.1142/s0218216503002299.

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In this paper, the easier methods of my thesis are applied to give a simple proof of a theorem of Goussarov. This theorem relates two possible notions of finite type equivalence of knots, links, or string links, showing that the resulting filtrations are the same up to a degree shift by a factor of two. This is then applied to the situation of rooted claspers to show that rooted clasper surgeries of sufficiently high degree must preserve type k invariants. As a consequence, grope cobordisms of sufficiently high class must preserve type k invariants. This result is applied in [CT] to show Theorem 2 of that paper.

8

WATANABE, TADAYUKI. "CLASPER-MOVES AMONG RIBBON 2-KNOTS CHARACTERIZING THEIR FINITE TYPE INVARIANTS." Journal of Knot Theory and Its Ramifications 15, no. 09 (November 2006): 1163–99. http://dx.doi.org/10.1142/s0218216506005056.

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Habiro found in his thesis a topological interpretation of finite type invariants of knots in terms of local moves called Habiro's Ck-moves. Ck-moves are defined by using his claspers. In this paper we define "oriented" claspers and RCk-moves among ribbon 2-knots as modifications of Habiro's notions to give a similar interpretation of Habiro–Kanenobu–Shima's finite type invariants of ribbon 2-knots. It works also for ribbon 1-knots. Furthermore, by using oriented claspers for ribbon 1-knots, we can prove Habiro–Shima's conjecture in the case of ℚ-valued invariants, saying that ℚ-valued Habiro–Kanenobu–Shima finite type invariant and ℚ-valued Vassiliev–Goussarov finite type invariant are the same thing.

9

Lessa, Rosângela Paula. "Contribuição ao conhecimento da biologia de Carcharhinus porosus Ranzani, 1839 (PISCES, CHONDRICHTHYES) das reentrâncias Maranhenses." Acta Amazonica 16 (1986): 73–86. http://dx.doi.org/10.1590/1809-43921986161086.

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184 machos da Carcharchinus porosas foram capturados com rede de emalhar nas Reentrâncias Maranhenses, entre Cururupu (1º 20' S e 45º W) e São Luis (2º 241 30'' S e 44º W) no período de outubro de 1983 à janeiro de 1984 e de junho à setembro de 1984. O desenvolvimento dos machos desta espécie foi estudado através da relação peso-comprimento e do crescimento: dos claspers, dos testículos, dos epidídimos e do fígado. Com exceção dos claspers e do fígado, o crescimento dos órgãos em questão é contínuo. No crescimento dos claspers evidenciou-se 3 fases que correspondem: a fase juvenil, a fase de adolescência e a fase adulta. Demonstrou-se, também, que existe uma descontinuidade no crescimento do fígado no momento da passagem da fase de adolescência à fase adulta, e que esta se verifica quando se relaciona o peso deste órgão com o peso corporal. Esfregaços do conteúdo da visívula seminal mostraram que o líquido branco presente neste órgão é livre de espermatozóides até 70 cm. Com base no crescimento dos claspers e na produção de espermatozóides normais, estabeleceu-se o tamanho de primeira maturidade em 71 cm (fim da fase de adolescência) e o tamanho de 100% de maturidade em 75 cm (início da fase adulta).

10

WHITE, WILLIAM T., FAHMI FAHMI, and SIMON WEIGMANN. "A new genus and species of catshark (Carcharhiniformes: Scyliorhinidae) from eastern Indonesia." Zootaxa 4691, no. 5 (November 4, 2019): 444–60. http://dx.doi.org/10.11646/zootaxa.4691.5.2.

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A new genus and species of catshark is described based on a single specimen collected off Ambon in the Maluku Islands of eastern Indonesia. Akheilos suwartanai belongs to the subfamily Schroederichthyinae which differs from the other catsharks in a combination of: similar sized dorsal fins, supraorbital crests present, pseudosiphon present on claspers, broad subocular ridges under eyes, posterior nasal flaps present, tips of rostral cartilage fused into a rostral node. It represents the first record of this subfamily outside of the Americas. Akheilos differs from the other genus in the subfamily, Schroederichthys in a combination of: clasper groove not fused dorsally, ventral lobe of caudal fin produced, more intestinal valve turns, anal fin slightly larger than second dorsal fin, and in colour pattern.

11

Pérez, Dante, Gabriela Olea, Tania Blanco Cohene, Evelyn Rodriguez Florencia, and Carolina Flores Quintana. "Dimorfismo sexual de las aletas pélvicas en Potamotrygon motoro (Batoidea: Potamotrigonidae)." Revista de Investigaciones Veterinarias del Perú 34, no. 5 (October 31, 2023): e24420. http://dx.doi.org/10.15381/rivep.v34i5.24420.

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Los claspers en los condrictios son alargamientos especializados en el lado posterior de las aletas pélvicas de los machos que se utilizan para la transferencia de esperma durante la cópula. El objetivo del presente estudio fue la descripción y caracterización de la morfología externa y los componentes esqueléticos en aletas pélvicas del clasper de Potamotrygon motoro (Batoidea: Potamotrygonidae). Se trabajó con tres ejemplares juveniles (2 machos y 1 hembra) y dos ejemplares adultos (1 macho y 1 hembra) provenientes del Rio Paraná, Corrientes Capital. Las muestras se fijaron en formol al 10%, y procesadas mediante la técnica de diafanización. El material fue conservado en glicerol para su observación. Macroscópicamente, el dimorfismo sexual se hace evidente en machos, mediante una estructura en la región posterior denominada clasper, de forma cónica ligeramente ahusada, visible dorsal y ventralmente. En muestras diafanizadas se puede distinguir los elementos cartilaginosos posteriores, diferenciándose un propterigio y un basipterigio, que unidos a este se localizan los segmentos basales y los cartílagos radiales de las aletas pélvicas; sin embargo, solo los machos desarrollan un clasper o mixopterigio. En las hembras, las únicas estructuras esqueléticas posteriores al basipterigio son pequeños elementos nodulares (cartílagos terminales). Se evidenció que estos ejemplares en sus primeros días de vida ya presentan el dimorfismo sexual asociado a la presencia de clasper en machos y su ausencia en hembras; sin embargo, los machos juveniles no presentan el desarrollo total del mixopterigio que forma el clasper.

12

Habiro, Kazuo. "Claspers and finite type invariants of links." Geometry & Topology 4, no. 1 (January 28, 2000): 1–83. http://dx.doi.org/10.2140/gt.2000.4.1.

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13

García Aldrete, Alfonso Neri, and Alberto Moreira da Silva Neto. "A new species of Lachesilla (Psocodea: Psocomorpha: Lachesillidae), in species group Corona, from Chiapas, Mexico." Dugesiana 25, no. 2 (July 28, 2018): 147–49. http://dx.doi.org/10.32870/dugesiana.v25i2.7049.

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A new species of Lachesilla, from the Mexican state of Chiapas, is described and illustrated, it is assigned to species group Corona on basis of the paraprocts, epiproct, and phallosome apodemes; the hypandrium and claspers do not seem to fit well into species group Corona.

14

JAMES, KELSEY C., DAVID A. EBERT, DOUGLAS J. LONG, and DOMINIQUE A. DIDIER. "A new species of chimaera, Hydrolagus melanophasma sp. nov. (Chondrichthyes: Chimaeriformes: Chimaeridae), from the eastern North Pacific." Zootaxa 2218, no. 1 (September 2, 2009): 59–68. http://dx.doi.org/10.11646/zootaxa.2218.1.3.

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A new species of chimaera, Hydrolagus melanophasma sp. nov. (Chimaeridae), is described from the eastern North Pacific. It is distinct from other eastern Pacific chimaeroids by the following characteristics: a large slightly curved dorsal fin spine extending beyond dorsal fin apex, a long second dorsal fin of uniform height throughout, large pectoral fins extending beyond the pelvic fin insertion when laid flat, trifid claspers forked for approximately one-quarter the total clasper length and a uniform black coloration throughout. The new species is compared to other eastern Pacific members of the genus Hydrolagus including H. alphus, H. colliei, H. macrophthalmus, and H. mccoskeri. Remote Operated Vehicle (ROV) video footage has identified and documented Hydrolagus melanophasma from the Gulf of California. ROV observations suggest that individuals typically occur over soft-bottom habitats or cobble patches with minimal vertical relief. This is in contrast to other eastern Pacific Hydrolagus species that tend to occur in areas of high rocky relief. The known distribution of this new species at present extends from southern California, U.S.A., along the Pacific coast of Baja California, Mexico, and into the Gulf of California.

15

Viana, Sarah, and Karla D. A. Soares. "Untangling the systematic dilemma behind the roughskin spurdog Cirrhigaleus asper (Merrett, 1973) (Chondrichthyes: Squaliformes), with phylogeny of Squalidae and a key to Cirrhigaleus species." PLOS ONE 18, no. 3 (March 6, 2023): e0282597. http://dx.doi.org/10.1371/journal.pone.0282597.

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Cirrhigaleus comprises a small genus of rare barbel-bearing dogfish sharks with distributions in limited regions of all oceans. Generic validity and taxonomic status of some species are upon controversies by morphological and molecular evidence that often suggest reallocation of Cirrhigaleus species into the genus Squalus. Particularly, the roughskin spurdog C. asper exhibits intermediary morphological characteristics within Squalidae that requires clarification. In the present study, a phylogenetic approach was undertaken to test the correct generic placement of C. asper using novel and revised morphological characters. We performed maximum parsimony analysis of 51 morphological characters of the internal (e.g., neurocranium, clasper cartilages, pectoral and pelvic girdles) and external anatomy applied to 13 terminal taxa. Cirrhigaleus represents a valid genus and it is supported by eight synapomorphies: high number of monospondylous vertebrae; medial nasal lobe supported by fleshy core and innervated by the buccopharyngeal branch of the facial nerve; neurocranium with greatest width across nasal capsules; one facet and one condyle in the puboischiadic bar for articulating with the basipterygium; two intermediate segments between the basipterygium of the pelvic fin and the axial cartilage of the claspers; five terminal clasper cartilages; and posterior medial process of the puboischiadic bar absent. Cirrhigaleus asper is sister-species to a small clade comprising C. barbifer and C. australis which is supported by one synapomorphy, presence of conspicuous cusplets in the dermal denticles. Cirrhigaleus barbifer, C. asper and C. australis are redescribed herein and the neotype of C. barbifer is designated. A key to Cirrhigaleus species is also given and the inner relationships within Squalus is tentatively discussed.

16

Ahlberg, Per, Kate Trinajstic, Zerina Johanson, and John Long. "Pelvic claspers confirm chondrichthyan-like internal fertilization in arthrodires." Nature 460, no. 7257 (July 13, 2009): 888–89. http://dx.doi.org/10.1038/nature08176.

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17

HABIRO, KAZUO. "Brunnian links, claspers and Goussarov–Vassiliev finite type invariants." Mathematical Proceedings of the Cambridge Philosophical Society 142, no. 3 (May 2007): 459–68. http://dx.doi.org/10.1017/s0305004107000072.

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AbstractGoussarov and the author independently proved that two knots in S3 have the same values of finite type invariants of degree <n if and only if they are Cn-equivalent, which means that they are equivalent up to modification by a kind of geometric commutator of class n. This property does not generalize to links with more than one component.In this paper, we study the case of Brunnian links, which are links whose proper sublinks are trivial. We prove that if n ≥ 1, then an (n+1)-component Brunnian link L is Cn-equivalent to an unlink. We also prove that if n ≥ 2, then L can not be distinguished from an unlink by any Goussarov–Vassiliev finite type invariant of degree <2n.

18

MEILHAN, JEAN-BAPTISTE. "ON VASSILIEV INVARIANTS OF ORDER TWO FOR STRING LINKS." Journal of Knot Theory and Its Ramifications 14, no. 05 (August 2005): 665–87. http://dx.doi.org/10.1142/s0218216505003993.

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We show that the Casson knot invariant, linking number and Milnor's triple linking number, together with a certain 2-string link invariant V2, are necessary and sufficient to express any string link Vassiliev invariant of order two. Explicit combinatorial formulas are given for these invariants. This result is applied to the theory of claspers for string links.

19

Soto-López, Katherin, Gabriela García-Vázquez, Julio C. Martínez-Ayala, Felipe Galván-Magaña, and Rosa I. Ochoa-Báez. "First record of clasper malformation of Pseudobatos buthi (Chondrichthyes: Rhinobatidae) in the Gulf of California." Journal of the Marine Biological Association of the United Kingdom 101, no. 2 (March 2021): 449–55. http://dx.doi.org/10.1017/s0025315421000175.

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AbstractElasmobranchs in the Gulf of California have been found with malformations, probably originated during embryonic development or caused by environmental anomalies and pollution associated with intense mining activity in the region. Clasper malformations are reported for the first time in two specimens of Pseudobatos buthi, a species recently described from the Gulf of California. The function of the claspers was not affected by the size difference, because specimens presented the distinctive characteristics of an adult individual. The reproductive system did not show any malformation, with symmetrical testes. Histological analysis of the testes revealed a normal spermatogenic development. To elucidate the causes and to detect a possible effect of the morphological malformations due to high levels of heavy metals, trace concentration values (cadmium, copper, iron, manganese, silver, lead and zinc) were determined in muscle and liver. Cadmium and lead concentrations in the muscle of the two specimens were below the permissible limit for human consumption (<0.05 mg kg−1); however, iron and zinc presented high values (0.455, 4.024 mg kg−1 in muscle and 21.931, 3.694 mg kg−1 in liver respectively). Mining activity and heavy metal pollution in the sampling area may have caused the malformations, which might be attributed to the high values of iron and zinc discovered in the muscle and liver.

20

Figueroa, Daniel Enrique, Mauro Belleggia, Gabriela Andreoli, Silvina Izzo, Nelson Bovcon, Marcos Pérez-Losada, Agustín María De Wysiecki, Jorge Horacio Colonello, and María Inés Trucco. "A Faunistic Revision of Longnose Skates of the Genus Dipturus (Rajiformes: Rajidae) from the Southern Southwestern Atlantic Ocean, Based on Morphological and Molecular Evidence." Diversity 16, no. 3 (February 25, 2024): 146. http://dx.doi.org/10.3390/d16030146.

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The identity of longnose skates (Dipturus-Zearaja-like skates) in the southern cone of the Americas has been a topic of extensive debate. This study employs a comprehensive analysis encompassing morphometrics, claspers, and the examination of COI and NADH2 sequence data to conclusively demonstrate the existence of only two longnose skate species in the southwestern Atlantic Ocean, extending south of 35 °S. Notably, Dipturus argentinensis Díaz de Astarloa, Mabragaña, Hanner and Figueroa, 2008 is revealed as a junior synonym of D. trachyderma (Krefft and Stehmann, 1975). Dipturus leptocaudus (Krefft and Stehmann, 1975) remains a northern valid species, but the specimen from the Falkland Islands (Malvinas) is recognized as a misidentification of D. trachyderma. Zearaja flavirostris (Philippi, 1892) and Dipturus lamillai Concha, Caira, Ebert and Pompert, 2019 are confirmed as junior synonyms of Zearaja brevicaudata (Marini, 1933). These findings contradict the previous report of six species within the same region over the last decade and underscore the presence of D. trachyderma and Z. brevicaudata south of 35 °S in the southwestern Atlantic. Additionally, this study notes the occurrence of only one specimen of Z. chilensis (Guichenot, 1848) in the Falkland Islands (Malvinas), suggesting an unusual frequency of this eastern Pacific skate in the southern Southwest Atlantic. Given that clasper morphology serves as the key distinguishing trait between Dipturus and Zearaja species, we provided a detailed analysis of the clasper characteristics of the Atlantic D. trachyderma, unequivocally situating it within Dipturus. The diagnostic characteristics include: (i) the presence of cartilage with the distal portion referred to as the sentinel, a feature absent in Zearaja; (ii) longer ventral terminal cartilage with the distal end referred to as the funnel, compared to Zearaja; and (iii) a non-spatulate distal lobe, a distinctive trait specific to Dipturus.

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ROGERS, D. CHRISTOPHER, TSO CHIA CHANG, and YUNG-CHUAN WANG. "A new Eocyzicus (Branchiopoda: Spinicaudata) from Taiwan, with a review of the genus." Zootaxa 4318, no. 2 (September 7, 2017): 254. http://dx.doi.org/10.11646/zootaxa.4318.2.2.

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We present the first record of Eocyzicus from Taiwan. Eocyzicus taiwanensis n. sp. can be distinguished from all other Eocyzicus species by the form of the claspers, the telson and the cercopods. This new species is so far known only from the type locality, which is a series of flood irrigated garlic fields in the Tainan District. The genus is reviewed superficially and revised conservatively. We recognize 19 Eocyzicus species, three nomina dubia and inquirendae, and 71 synonyms.

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LI, YAJIN, NTIRENGANYA ELIE, HUI LIU, and HONGRUI ZHANG. "Aduncothrips newly recorded from China, with three new species and a new generic synonym (Thysanoptera: Aeolothripidae)." Zootaxa 5141, no. 1 (May 24, 2022): 49–59. http://dx.doi.org/10.11646/zootaxa.5141.1.4.

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The previously monotypic genus Aduncothrips Ananthakrishnan from India is newly recorded from China with three new species: A. albus sp. n., A. huapingensis sp. n., A. kailiensis sp. n. The genus Desmidothrips Mound from Australia is synonymized with Aduncothrips, and the Japanese species A. japonicus (Masumoto & Okajima) is newly recorded in China with first description of the male. A key to the seven known species of Aduncothrips is provided. Males in this genus, where known, have maxillary palps 3-segmented with segment II undivided, and tergite IX without claspers.

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Moreno-García, Miguel, and Carlos Cordero. "On the function of male genital claspers in Stenomacra marginella (Heteroptera: Largidae)." Journal of Ethology 26, no. 2 (September 14, 2007): 255–60. http://dx.doi.org/10.1007/s10164-007-0058-8.

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24

DeMilo, Albert B., Dale B. Gelman, and Barna Bordás. "Benzoylbiuret Insect Chitin Inhibitors: Structure-Activity Correlations Derived from an In vitro Clasper Assay and an In vitro Mosquito Adult Emergence Assay2." Journal of Entomological Science 32, no. 2 (April 1, 1997): 212–28. http://dx.doi.org/10.18474/0749-8004-32.2.212.

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Chitin-synthesis inhibitory effects of nine l-benzoyl-5-phenyl-biurets and six l-benzoyl-5-phenyl-4-thiobiurets were determined in an in vitro assay using male pharate adult claspers of the European corn borer, Ostrinia nubilalis (Hübner). Incorporation of labeled N-acetylglucosamine into the clasper tissue was effectively inhibited by the benzoylbiurets (IC50 values ranged from 0.032 to 8.2 ppm). Quantitative structure-activity relationships of the benzoylbiurets were analyzed by linear regression analysis. The analysis used yellowfever mosquito (Aedes aegypti (L.)) adult emergence data (LC50 values) and in vitro chitin-synthesis inhibition data (IC50 values) as biological endpoints and a set of physicochemical parameters (independent variables) of the para substituent of the anilide moiety. Stepwise regression analysis of the in vivo data provided a significant four-parameter equation involving Hammett σp and Hansch-Fujita π constants, and two indicator variables. Analysis of the in vitro chitin-synthesis inhibition data yielded a significant two-parameter equation incorporating σp and an indicator variable. In vitro larvicidal activity against A. aegypti and the house fly (Musca domestica L.) was enhanced by electron-withdrawing and lipophilic substituents in the para position of the anilide moiety. In contrast, in vitro chitin-synthesis inhibition was favored by electron-donating substituents. It was suggested that the equations derived from in vivo activity data describe mainly pharmacokinetic processes such as transport and metabolism. Structural requirements for intrinsic activity of the benzoylbiurets at the putative receptor site were better represented by the equation derived from the in vitro chitin-synthesis inhibition data.

25

jones, a. a., w. t. white, and i. c. potter. "a hermaphroditic port jackson shark, heterodontus portusjacksoni, with complete and separate female and male reproductive tracts." Journal of the Marine Biological Association of the United Kingdom 85, no. 5 (October 2005): 1171–72. http://dx.doi.org/10.1017/s0025315405012269.

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one of 353 port jackson sharks, heterodontus portusjacksoni, caught off the southern coast of western australia, was a hermaphrodite. the female reproductive tract consisted of a large (functional) right ovary with three large yolked ova, a small non-functional left ovary and two well-developed uteri and oviducal glands. the male tract comprised two conspicuous but undeveloped testes, two vas deferens and two calcified claspers with grooves. this individual represents the first published example of hermaphroditism in the order heterodontiformes and is a rare example of an elasmobranch with a complete suite of both male and female reproductive structures.

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GAROUFALIDIS, STAVROS. "THE MYSTERY OF THE BRANE RELATION." Journal of Knot Theory and Its Ramifications 11, no. 05 (August 2002): 725–37. http://dx.doi.org/10.1142/s0218216502001925.

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Using the notion of surgery on objects called Y-graphs and claspers by Goussarov and Habiro, one can define a theory of finite type invariants of closed 3-manifolds. The paper discusses upper bounds for the number of invariants, and focuses on two surprises that arise: One surprise is that the upper bounds depend on a bit more than a choice of generators for H1. A complementary surprise a curious brane relation (in two flavors, open and closed) which shows that the upper bounds are in a certain sense independent of the choice of generators of H1.

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JACOBSEN, IAN P., and MIKE B. BENNETT. "Description of a new species of catshark, Atelomycterus marnkalha n. sp. (Carcharhiniformes: Scyliorhinidae) from north-east Australia." Zootaxa 1520, no. 1 (July 5, 2007): 19–36. http://dx.doi.org/10.11646/zootaxa.1520.1.2.

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A new atelomycterine catshark species (Scyliorhinidae: Atelomycterinae), Atelomycterus marnkalha n. sp., is described from north-east Australia (Great Barrier Reef Marine Park, Torres Strait and Gulf of Carpentaria). It differs from A. baliensis, A. marmoratus and A. macleayi in having posteroventally sloping dorsal fins, a lower precaudal vertebrae count and smaller adult size. Most similar to the Western Australian catshark species A. fasciatus, A. marnkalha differs from this species in having a larger anal fin, lateral denticles with prominent shallow depressions, claspers of adult males with a cover rhipidion lacking an obvious notch and its colour pattern with prominent white spots and fewer, smaller black spots.

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Myers, Shelley S., Thomas R. Buckley, and Gregory I. Holwell. "Male genital claspers influence female mate acceptance in the stick insect Clitarchus hookeri." Behavioral Ecology and Sociobiology 70, no. 9 (July 11, 2016): 1547–56. http://dx.doi.org/10.1007/s00265-016-2163-6.

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29

Lott, Micah. "Practical Intelligibility and Moral Skepticism: Should Realists Worry About Grass‐Counters and Hand‐Claspers?" Pacific Philosophical Quarterly 102, no. 1 (February 16, 2021): 103–25. http://dx.doi.org/10.1111/papq.12334.

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30

SÉRET, BERNARD, and PETER R. LAST. "Galeus priapus sp. nov., a new species of sawtail catsharks (Carcharhiniformes: Scyliorhinidae) from New Caledonia." Zootaxa 1813, no. 1 (June 30, 2008): 19. http://dx.doi.org/10.11646/zootaxa.1813.1.2.

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Galeus priapus sp. nov. is described from specimens collected on the slopes of the seamounts and ridges of southern New Caledonia and Vanuatu. It is the first Galeus species recorded in these areas. G. priapus is characterised by the presence of a conspicuous crest of enlarged denticles on the dorsal caudal margin, the absence of similar crest on ventral caudal margin, and extremely long and slender claspers in adult males that extend posteriorly to the anal-fin origin. The body coloration, which is plain greyish brown with large dark blotches on dorsal and caudal fins and their bases, closely resembles its sibling G. gracilis, a northern Australian and Indonesian species. An identification key to Indo-Pacific Galeus species is provided.

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Arisandi, Arisandi, Arsana I N., and Sudaryati N.L.G. "KOMPOSISI UKURAN DAN JENIS KELAMIN IKAN HIU KARANG SIRIP HITAM (CARCHARHINUS MELANOPTERUS) KOMODITAS EKSPOR BALI." JURNAL WIDYA BIOLOGI 11, no. 01 (March 28, 2020): 52–59. http://dx.doi.org/10.32795/widyabiologi.v11i01.570.

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Penelitian bertujuan untuk mengetahui komposisi ukuran dan jenis kelamin ikan hiu karang sirip hitam (Carcharhinus melanopterus). Penelitian dilaksanakan menggunakan metode observasi lapangan. Sampel didapat dari sepuluh perusahaan eksportir ikan hiu di Provinsi Bali. Variabel yang diukur adalah panjang tubuh dan jenis kelamin ikan hiu. Panjang tubuh diukur dari ujung mulut sampai dengan ujung ekor. Jenis kelamin dibedakan berdasarkan adanya claspers. Data yang diperoleh kemudian dianalisis secara deskriptif. Hasil penelitian mendapatkan sebanyak 208 ekor ikan hiu karang sirip hitam (Carcharhinus melanopterus) komoditas ekspor Bali. Sebanyak 149 ekor (71,63 %) ikan berjenis kelamin betina, dengan panjang tubuh rata-rata 48 cm. Sedangkan ikan hiu berjenis kelamin jantan sebanyak 59 ekor (38,37 %) dengan rata-rata berukuran 50 cm. Kesimpulan, komposisi ukuran tubuh dan jenis kelamin ikan hiu karang sirip hitam (Carcharhinus melanopterus) komoditas ekspor Bali bervariasi berdasarkan jenis kelamin.

32

Hewitt, Chad L., and Jeffrey HR Goddard. "A new species of large and highly contractile hydroid in the genus Candelabrum (Hydrozoa: Anthoathecatae) from southern Oregon, U.S.A." Canadian Journal of Zoology 79, no. 12 (December 1, 2001): 2280–88. http://dx.doi.org/10.1139/z01-198.

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A new species of hydroid, Candelabrum fritchmanii, is described from Cape Arago, Oregon, U.S.A. Specimens were collected from the intertidal region underneath boulders. This new species' standing with respect to other members of the genus is discussed. The claspers in the blastostylar region of the new species show similarities to the North Atlantic Candelabrum cocksii. However, three specimens had multiple, connected polyps at varying stages of development and the cnidome differs between C. cocksii and the new species, leading to the erection of a new species. The polyp cnidome consists of desmonemes, heteronemes (microbasic mastigophores and homotrichous microbasic euryteles), and stenoteles and the actinula cnidome consists of desmonemes, haplonemes (atrichous isorhizas), and stenoteles. Emendations to the family, subfamily, and genus diagnoses are presented to accommodate these findings. Observations are also presented on actinula development and the ensnaring, predatory feeding behavior of the highly contractile polyp.

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KEMPER, JENNY M., DAVID A. EBERT, LEONARD J. V. COMPAGNO, and DOMINIQUE A. DIDIER. "Chimaera notafricana sp. nov. (Chondrichthyes: Chimaeriformes: Chimaeridae), a new species of chimaera from southern Africa." Zootaxa 2532, no. 1 (July 12, 2010): 55. http://dx.doi.org/10.11646/zootaxa.2532.1.2.

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A new species of chimaera, Chimaera notafricana sp. nov., is described from specimens collected off the west and south coasts of southern Africa. The new species is distinguished from its closest congener, the eastern North Atlantic Chimaera monstrosa, by a combination of morphometric characters and coloration: pectoral fin when depressed reaches to origin of pelvic fin base; caudal fin ventral margin terminating slightly posterior to caudal fin dorsal margin insertion; distance from anterior base of dorsal-fin spine to center of supratemporal canal short (6.5–14.8% HDL); pelvic claspers externally trifid and short (12.1–12.3% BDL), divided for distal one-third of length, not extending past distal tip of pelvic fins; uniform blackish brown with dark bluish streaking, precaudal tail with longitudinal light and dark stripes. This new species has a restricted distribution from Lüderitz, Namibia to south of Algoa Bay, Eastern Cape Province, South Africa.

34

Shen, Yan-Bin, and Frederick R. Schram. "Soft-body preservation in the leaiid clam shrimp (Branchiopoda, Diplostraca) and its palaeoecological implications." Crustaceana 87, no. 11-12 (2014): 1338–50. http://dx.doi.org/10.1163/15685403-00003349.

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Leaia is a special genus of extinct “conchostracan” branchiopods; its soft parts have not been known until now. The leaiid specimens with soft bodies reported in the present paper came from two localities: the Upper Carboniferous Canso Group of New Brunswick, Canada, and the Permian Mount Glossopteris Formation of the Ohio Range, Holick Mountains, Antarctica. They include head, biramous antennae, mandible, shell gland, male claspers, and digestive tube. These parts together fully demonstrate that the leaiid clam shrimp indeed should be attributed to the crustaceans, instead of Mollusca. Based on the ribbed valves and structure of soft parts it should be placed in the branchiopodan Diplostraca. We believe that this group, which went extinct at the end of the Permian, is quite different from those of Laevicaudata, Spinicaudata, and Cyclestheriida. Hence, it should have its own higher taxon, Leaiina. The well-developed and sharply pointed head, delicate and short biramous antennae, in concert with the radial ribs on the valves probably indicate a burrowing in-faunal habit.

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WALOVICH, KRISTIN A., DAVID A. EBERT, and JENNY M. KEMPER. "Hydrolagus erithacus sp. nov. (Chimaeriformes: Chimaeridae), a new species of chimaerid from the southeastern Atlantic and southwestern Indian oceans." Zootaxa 4226, no. 4 (January 30, 2017): 509. http://dx.doi.org/10.11646/zootaxa.4226.4.4.

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A new species of chimaerid, Hydrolagus erithacus sp. nov., is described from nine specimens collected from the southeast Atlantic and southwest Indian oceans from depths of 470–1,000 meters. This species is distinguished from all other Hydrolagus species based on the following characteristics: head bulky, relatively large, followed by stocky body; head and body height from about pectoral fin origin to pelvic fin origin similar, then tapering rapidly to filamentous tail; first dorsal fin spine height about equal to, or slightly less than first dorsal fin apex height; second dorsal fin up to 81% of total body length and uniform in height; trifurcate claspers forked for approximately 20% of total length; robust frontal tenaculum nearly uniform in width, prepelvic tenaculae with five to seven medial spines, and a uniform black coloration with robust, non-deciduous skin. Comparison of mitochondrial NADH2 gene sequences with other morphologically similar Hydrolagus species suggests that H. erithacus is a distinct species.

36

Moreno, J., and J. Moron. "Reproductive biology of the Bigeye Thresher Shark, Alopias superciliosus (Lowe, 1939)." Marine and Freshwater Research 43, no. 1 (1992): 77. http://dx.doi.org/10.1071/mf9920077.

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More than 1000 specimens of Alopias superciliosus from fisheries exploited by the Spanish fishing fleet in the north-eastern Atlantic Ocean (from Cape SLo Vicente to the Ivory Coast) and in the western Mediterranean Sea (i.e. west of an imaginary line between Monaco and Algiers) were observed in discontinuous samples between 1981 and 1989. Ten gravid females, 20 fetuses and a large number of egg capsules were studied in detail. The embryo morphology provided evidence of ovophagy. Size at birth was probably at least 100 cm. Six males with total lengths of 400-410 cm exceeded the previously reported maximum length for this sex. The characteristics of the claspers and deferent ducts suggested a total length at maturity of about 276 cm for males. The smallest gravid female was 341 cm long. Also described are litter sizes, indications of reproductive seasonality, and the possible existence of a nursery area in waters off the south-western Iberian peninsula.

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costa, m. e., k. erzini, and t. c. borges. "reproductive biology of the blackmouth catshark, galeus melastomus (chondrichthyes: scyliorhinidae) off the south coast of portugal." Journal of the Marine Biological Association of the United Kingdom 85, no. 5 (October 2005): 1173–83. http://dx.doi.org/10.1017/s0025315405012270.

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the reproductive biology of 1045 female (9.5–67 cm (total length (tl)) and 1007 male (9.4–64.3 cm tl) blackmouth catsharks, galeus melastomus, was investigated. the sharks were caught off southern portugal by bottom crustacean trawlers at depths from 209 to 754 m. the sex ratio was 1:1, and this species is sexually dimorphic with males approaching maturity at smaller size than females. sexual segregation appears to be given for the stock within the study area. sexual maturity was reached at a total length above 49 cm in males and above 56 cm in females. mating and egg-deposition take place all year round, with two reproductive peaks of activity, in winter and summer. egg capsules are, on average, 54 mm long and 21 mm wide, with a maximum of 63×25 mm encountered. morphometric measurements of claspers, testes, ovaries, and oviducal glands were suitable for determining sexual maturity of blackmouth catshark.

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Gračan, Romana, and Gordana Lacković. "Histological and Morphological Aspects of Reproduction in Male Blackspotted Smooth-HoundMustelus punctulatusin the Adriatic Sea (Eastern Mediterranean Sea)." Journal of Marine Biology 2016 (2016): 1–6. http://dx.doi.org/10.1155/2016/3438678.

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We present first data on reproductive biology of male blackspotted smooth-houndMustelus punctulatusin the Adriatic Sea and first histological examination of gonads at different maturation stages and seasonal cycles for this species. We collected samples from 117 male specimens ofM. punctulatusranging in length from 44.6 to 126.5 cm, caught by commercial bottom trawls in the North-Central Adriatic Sea. Microscopic observation revealed a diametric development of testes, in which round-shaped spermatocysts have zonal arrangement, showing seven different stages of development. Males began to mature when they were between 61 and 88 cm body length, which was indicated by the presence of functional claspers or appearance of the spermatogenic cysts. While the smallest mature shark was only 80 cm long, all animals longer than 89 cm were sexually mature. The seasonal analysis of the testes indicated that mature spermatozoa dominated in testes during the first half of the year with a peak in May and June, after which followed less active period during July and August.

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Medeiros, Gleyce da Silva, Rudy Camilo Nunes, Feng Zhang, Nerivânia Nunes Godeiro, and Bruno Cavalcante Bellini. "A New Genus of Sminthurididae (Collembola, Symphypleona) from Brazil, with Notes on the Systematics of the Family." Diversity 14, no. 11 (November 9, 2022): 960. http://dx.doi.org/10.3390/d14110960.

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The Sminthurididae family includes Symphypleona species highly adapted to courtship, with males exhibiting remarkable modifications on their antennae. Here we describe a new Neotropical genus and species of Sminthurididae from a Cerrado-Caatinga ecotonal zone in Brazil. Males of Parasminthurides spinosus gen. nov. sp. nov. have highly dimorphic antennal claspers similar to those of Sminthurides, but its females have unique strong spiniform chaetae on antennal segments II and III as well, which are possibly accessories for the courtship. The new genus can also be diagnosed by its elongated maxillae, males having large dorsal vesicles between abdomen II and III, ungues I–III with similar morphology and sizes, and interno-apical dental chaetae modified into large spiniform chaetae. We also present the main diagnostic features of all Sminthurididae genera, providing a comparative table and an updated identification key for them. Finally, we discuss the previous and current knowledge on the family’s systematics, suggesting some perspectives for future studies in this field.

40

Wang, Yu-Hui, Dina Espinoza Rivera, William Klobasa, and Marcé D. Lorenzen. "Evaluation of Peregrinus maidis transformer-2 as a target for CRISPR-based control." PLOS ONE 19, no. 4 (April 18, 2024): e0295335. http://dx.doi.org/10.1371/journal.pone.0295335.

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The corn planthopper, Peregrinus maidis, is an economically important pest of corn and sorghum. Here we report the initial steps towards developing a CRISPR-based control method, precision guided sterile insect technique (pgSIT), for this hemipteran pest. Specifically, we evaluated the potential of transformer-2 (tra-2) as a target for sterilizing insects. First, we identified tra-2 transcripts within our P. maidis transcriptome database and performed RNA interference (RNAi) to confirm functional conservation. RNAi-mediated knockdown of Pmtra-2 in nymphs transformed females into pseudomales with deformed ovipositors resembling male claspers. While males showed no overt difference in appearance, they were indeed sterile. Importantly, the results were similar to those observed in another planthopper, Nilaparvata lugens. We also used CRISPR/Cas9 genome editing to assess the impact of tra-2 knockout in injectees. CRISPR-mediated knockout of Pmtra-2 had lethal effects on embryos, and hence not many injectees reached adulthood. However, mosaic knockout of Pmtra-2 did impact female and male fertility, which supports the use of tra-2 as a target for pgSIT in this hemipteran species.

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Challier, A., and F. L. Lambrecht. "A new morphological character of superior claspers to differentiate Glossina pallidipes Austen from Glossina Longipalpis Wiedemann (Diptera: Glossinidae)." International Journal of Tropical Insect Science 6, no. 06 (December 1985): 719–21. http://dx.doi.org/10.1017/s1742758400002964.

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42

Mello, Francisco de A. G. de. "Female monopolization and paternity assurance in South American crickets (Orthoptera, Grylloidea): mating plugs, extra claspers and forced copulation." Papéis Avulsos de Zoologia 47, no. 20 (2007): 245–57. http://dx.doi.org/10.1590/s0031-10492007002000001.

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This paper describes the first three cases in which male crickets monopolize females by means of mating plugs. The origin of the plugs vary among the cases (i.e., they are not homologous). Female monogamy is assured by the permanent presence of the plug attached to their genitalia after first mating, while males are potentially polygamous. The presence of an additional clasping structure and the occurrence of forced copulation are also described.

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Kaji, Tomonari, Martin Fritsch, Martin Schwentner, Jørgen Olesen, and Stefan Richter. "Male claspers in clam shrimps (Crustacea, Branchiopoda) in the light of evolution: A case study on homology versus analogy." Journal of Experimental Zoology Part B: Molecular and Developmental Evolution 322, no. 5 (May 8, 2014): 269–80. http://dx.doi.org/10.1002/jez.b.22574.

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44

Wang, Kai-Xuan, Chun-Bing Chen, Qiu-Xing Wan, and Xing-Fu Zha. "Long Non-Coding RNA Bmdsx-AS1 Effects on Male External Genital Development in Silkworm." Insects 13, no. 2 (February 11, 2022): 188. http://dx.doi.org/10.3390/insects13020188.

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Long non-coding RNAs (lncRNAs) have been suggested to play important roles in some biological processes. However, the detailed mechanisms are not fully understood. We previously identified an antisense lncRNA, Bmdsx-AS1, that is involved in pre-mRNA splicing of the sex-determining gene Bmdsx in the silkworm. In this study, we analyzed the changes in the male external genitalia of transgenic overexpressed Bmdsx-AS1 silkworm lines and analyzed downstream and upstream responses. We found that Bmdsx-AS1 transgenic silkworms, compared with wild type, showed more claspers in the male external genitalia. Quantitative real-time PCR (qPCR) results indicated that overexpression of Bmdsx-AS1 decreased the expression of genes in the EGFR signaling pathway. Knockdown of Bmdsx-AS1 increased the activity of the EGFR pathway. Through promoter prediction, promoter truncation and electrophoretic mobility shift assay (EMSA) analyses, we found that the protein encoded by the Hox gene BmAbd-B specifically binds to the promoter of Bmdsx-AS1. Moreover, overexpression of BmAbd-B in the silkworm BmE cell line indicated that BmAbd-B negatively regulates the mRNA expression of Bmdsx-AS1. Our study provides insights into the regulatory mechanism of the lncRNA in the silkworm.

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Long, John A., and Kate M. Trinajstic. "A review of recent discoveries of exceptionally preserved fossil fishes from the Gogo sites (Late Devonian, Western Australia)." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 108, no. 1 (March 2017): 111–17. http://dx.doi.org/10.1017/s1755691018000178.

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ABSTRACTSignificant new material of Late Devonian Gogo Formation fish fossils is still surfacing. Collecting in the past decade has uncovered the first Gogo shark fossils (Gogoselachusplus another new undescribed taxon), the first acanthodian (Halmacanthodes ahlbergi), the first coelacanth, as well as the first placoderm embryos. Recent studies have elucidated the nature of placoderm claspers, pelvic girdles, synarcuals and embryos, the structure of their teeth, a description of well-preserved muscles in placoderms, and how muscles attach to bones. Molecular biomarkers have also been identified in Gogo fossils. There are now five basal ray-fin fishes in the fauna, including one undescribed new taxon. The lungfish fauna from Gogo is the most diverse known for any Devonian site, with 10 genera and 12 species. The dermal skeleton and endocast of the dipteridRhinodipterus kimberleyensishave been described in detail from CT scans; and the ontogenetic stages of neurocranium formation inGriphognathus. New specimens of the tetrapodomorph fishGogonasus andrewsaehave shed further light on its endocranium, pectoral girdle and fin. Through their exceptional preservation of both hard and varied kinds of soft tissues, the Gogo fishes remain crucial for resolving key debates on the diversification, physiology, biomechanics and phylogenetic relationships of early gnathostomes.

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Megalofonou, Persefoni, Dimitris Damalas, and Gregorio de Metrio. "Biological characteristics of blue shark, Prionace glauca, in the Mediterranean Sea." Journal of the Marine Biological Association of the United Kingdom 89, no. 6 (May 6, 2009): 1233–42. http://dx.doi.org/10.1017/s0025315409000216.

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A total of 870 blue sharks ranging from 70 to 349 cm in total length (LT) were sampled from the swordfish longline fishery in the Mediterranean Sea during the period 1998–2003. Males predominated and the sex-ratio (1:1.8) showed an increase in the proportion of males as size of fish increased. Gonad observation revealed that females smaller than 120 cm LT had immature ovaries with no mature oocytes, while mature ovaries with visible yolky oocytes were present in specimens larger than 203 cm LT. Ovary weight varied from 4–137 g and maximum oocyte diameter was 21.1 mm in mature females. All males smaller than 125 cm LT were immature while males larger than 187 cm LT were mature, as indicated by the presence of heavily calcified claspers, which extended beyond the posterior end of the pelvic fins. Length at 50% maturity (L50) was estimated to be 202.9 cm LT for males and 214.7 cm LT for females. Age estimates using caudal vertebrae ranged from 1 to 12 years, while age at 50% maturity was estimated at 4.9 years for males and 5.5 year for females.

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Rizkiantino, Rifky, and Ridzki M. F. Binol. "Septicemic Infection Suspect In Jenkins' Whipray Pateobatis jenkinsii (Annandale, 1909): A Case Report." Jurnal Sain Veteriner 38, no. 1 (April 1, 2020): 69. http://dx.doi.org/10.22146/jsv.48850.

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A wild-captive male Jenkins' whipray was found dead in a quarantine tank with a clinical sign before death in the form of decreased appetite for a week. The treatment history was oral administration of enrofloxacin antibiotic tablets. The therapy period lasts for ten days. The last treatment was the administration of Hepavit® (liver extract) and intramuscular injection of enrofloxacin antibiotic. One day before the death, blood was collected and then examined for the hematocrit and some parameters of chemical blood. The results of blood examination were found a decrease in blood urea nitrogen (BUN), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) levels, increased glucose level, decreased total protein and albumin levels, and increased globulin level. Anatomical pathology examination was found lesions on the tail, around the eyes, and claspers. Hemorrhagic lesions were found in the mucous layer of the esophagus, stomach, and spiral colon. The blood clot was found under the tunica layer of testicular organs. The liver is damaged by showing a non-homogeneous coloration, organ thickening, congestion, and fragile consistency. Based on the results of the blood examination and was supported by the results of the anatomical pathology examination after death, it is suspected that the fish died due to the condition of septicemia infection during the previous few weeks.

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BARBOSA, JULIANNA FREIRES, JOSÉ RICARDO INACIO RIBEIRO, and RUTH LEILA FERREIRA-KEPPLER. "A new species of Martarega White, 1879 (Hemiptera: Heteroptera: Notonectidae) from the State of Pará, Brazil, and new records for three species in Brazil." Zootaxa 2351, no. 1 (February 4, 2010): 58. http://dx.doi.org/10.11646/zootaxa.2351.1.6.

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Members of Martarega White are stream inhabitants and tend to be gregarious, forming large schools in deep sheltered eddies. Most of the species of Martarega are known from Neotropics, and nine of them have been reported from Brazil. Martarega oriximinaensis Barbosa, Ribeiro and Ferreira-Keppler, sp. nov. is described here from Oriximiná, Pará. This species resembles M. hungerfordi Truxal in having a sharp concavity in the hind trochanter, and a narrow median stripe in the hemelytra and teeth in the costal margin of female hemelytra; but members of M. oriximinaensis can be readily recognized by the presence of one or two groups of very cohesive, short bristles near the lateral margin of the middle trochanter and by the distinctive shape of the male claspers. In M. oriximinaensis sp. nov. the female hemelytra bear at least 30 teeth on its costal margin, whereas in M. hungerfordi the female hemelytra bear at least sixteen teeth on such costal margin. A key to the species of Martarega occurring in northern Brazil is provided. New records of M. brasiliensis Truxal and M. membranacea White from Pará State (northern Brazil) are given. Members of M. uruguayensis (Berg) are newly recorded from São Paulo State (southeastern Brazil).

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Galván-Tirado, C., F. Galván-Magaña, and R. I. Ochoa-Báez. "Reproductive biology of the silky shark Carcharhinus falciformis in the southern Mexican Pacific." Journal of the Marine Biological Association of the United Kingdom 95, no. 3 (December 30, 2014): 561–67. http://dx.doi.org/10.1017/s0025315414001970.

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Despite being one of the most abundant and highly exploited species in the Mexican Pacific Ocean, information on the biology of the silky shark, Carcharhinus falciformis is limited. The objective of the present study was to describe the reproductive biology of this species, based on 262 sharks (117 females and 145 males) caught from September 2004 to May 2006 in the Gulf of Tehuantepec, Mexico. The size of females ranged from 70 to 229 cm total length (TL); males measured from 69 to 220 cm TL. Female reproductive organ measurements showed that between 175 and 190 cm TL there was an increase in oviducal gland width (19–45 mm), as well as in uterus size (20–220 mm width). Mature males over 180 cm had calcified claspers, well-developed testes (184–282 mm) and presence of sperm in the seminal vesicles. The estimated length of males at first maturity was 180 cm, and that of females was 190 cm. Ovarian fecundity varied from 4 to 11 oocytes, and uterine fecundity varied from 2 to 14 embryos. We infer that mating occurs between May and June. We did not find sperm storage in the oviducal glands. Birth size was observed to be between 60 and 69 cm TL. No defined gestation period was observed.

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Kukalová-Peck, Jarmila. "Ephemeroid wing venation based upon new gigantic Carboniferous mayflies and basic morphology, phylogeny, and metamorphosis of pterygote insects (Insecta, Ephemerida)." Canadian Journal of Zoology 63, no. 4 (April 1, 1985): 933–55. http://dx.doi.org/10.1139/z85-139.

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Gigantic as well as very large mayflies from the middle Upper Carboniferous (Westphalian) strata of Europe and North America are described: the adult and nymph of Bojophlebia prokopi n. gen., n. sp. (Bojophlebiidae n. fam.) and the nymphs of Lithoneura piecko n. sp. and Lithoneura clayesi n. sp. (Syntonopteridae). Evolution of ephemerid wing venation during 300 million years is summarized. Autapomorphic, apomorphic, and plesiomorphic character states of venation are categorized. Venational nomenclature of Recent Ephemerida is emended based on its evolutionary changes. Evidence that wing veins occurred primitively as a pair of fluted sectors is documented in Carboniferous mayflies in the costa, subcosta, radius, anal, and jugal. Ephemeroids and odonatoids are sister groups that share the veinal anal brace AA fused with CuP at an area important for flight. Ancestral Odonatoephemerida are the sister group of the extinct haustellate Paleoptera. The Carboniferous nymphs bear three pairs of almost homonomous thoracic wings and, on the abdomen, nine pairs of legs and nine pairs of tracheal gills (wing homologues). This proves that abdominal legs have been totally reduced in Recent Ephemerida except for the claspers (gonopods) and that tracheal gills are not flattened legs. The metamorphic instar probably originated in relatively young instars. Insectan cerci developed from segmented, arched, functional legs of abdominal segment 11, which were still present in this primitive condition in Carboniferous Monura.

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