genital papilla
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Author(s):  
Rickard Westerman ◽  
Mohammed Ahmed ◽  
Oleksandr Holovachov

AbstractTwo new species of nematodes associated with crabs are described from New Caledonia. Gammarinema scyllaesp. n. from the gill chambers of Scylla serrata (Forsskål) is characterised by 3–4 mm long body, small outer labial and cephalic sensilla, distinct ocelli, short straight spicules and sub-cylindrical tail. Monhystrium mangrovisp. n. from the gill chambers and body cavity of mangrove crab Neosarmatium sp. is characterised by 1–1.4 mm long body; outer labial sensilla longer than cephalic sensilla, amphid located at level with posterior stoma chamber, denticles in posterior stoma chamber and five pairs of genital papilla on tail. Phylogenetic relationships of two new species and other nematodes from the family Monhysteridae are analysed based on 18S and partial 28S rDNA sequences.


Nematology ◽  
2021 ◽  
pp. 1-15
Author(s):  
Elena S. Ivanova ◽  
Sergei E. Spiridonov

Summary Phasmarhabditis quinamensis sp. n. was recovered from several tropical terrestrial gastropod species collected in Cat Tien National Park in southern Vietnam with the snail, Sesara sp., designated as the type host. Phasmarhabditis quinamensis sp. n. is recognised by males and females with a lip region set off by the circle of six triangular low probolae, three bilobed, separated lips, stoma nearly as wide as long, the first genital papilla in males not incorporated into the bursa, the ensheathed dauer juveniles more than 1 mm long and with two circles of papillae at the head end and prominent amphidial apertures, a long filamentous tail and, when exsheathed, with a short, conical tail ending with two tiny spikes. The head structure of P. quinamensis sp. n. differentiates it from all nominal species of Phasmarhabditis. Phasmarhabditis quinamensis sp. n. is the second species of the genus found in Cat Tien National Park. The sympatric species P. meridionalis was also found during the present study. Phylogenetically, both species belong to different lineages within Phasmarhabditis. The molecular analysis based on partial sequences of LSU rDNA, and ITS rDNA regions showed P. kenyaensis to be the closest species to P. quinamensis sp. n.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Antônio Queiroz Lezama ◽  
Luiz R. Malabarba

ABSTRACT The function of the genital and anal papillae for insemination in Compsura heterura is discussed based on the description of their morphologies at different stages of the life cycle and during copulation and spawning. In males and females both the genital and anal papillae are involved in copulation in C. heterura. A pre-anal organ, anterior to the anus and stretched posteriorly, is present in adult males. The openings of the urinary channel and oviduct are separate in females. During copulation, there is an approximation between the female genital and anal papillae which become temporarily juxtaposed, forming a chamber enclosing the opening of the oviduct, which may also function in sperm capture. During spawning, the lateral edges of the female genital papilla are projected anteriorly, acquiring a tubular shape for oviposition.


2020 ◽  
Vol 13 (1) ◽  

Chitala ornata (J.E. Gray) (Osteoglossiformes: Notopteridae) has since established abundant and nuisance populations in Laguna de Bay. A fundamental prerequisite for the development of management strategies for invasive species like C. ornata is a full understanding of its life history characteristics including sexual dimorphism. In the present study, we examined the sexual dimorphism of C. ornata. Sexes of C. ornata can be distinguished through the examination of its genital papilla wherein females show distinct morphological adaptions for effective oviposition on a spawning substrate. Comparison of means and multivariate analysis of several morphometric characters showed that sexual size dimorphism in C. ornata is female-biased which is mainly attributed to the disparity of resource expenditure between sexes for reproduction and size-dependent advantages of females in the production of more progenies with better chances of survival.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Hirut Geremew ◽  
Melesse Abdisa ◽  
Goraw Goshu

The aim of the study was to determine the proximate composition of each sex of Oreochromis niloticus, Clarias gariepinus and Labeobarbus intermedius fish species from the southern Gulf of Lake Tana, Ethiopia. The fish samples were collected during the dry season of 2014 from the three fish landing sites, i.e., Bata, Micheal and Giorgis, where local fishermen sell their catches. Species were identified via morphological examination and color. Sexes were identified by observing genital papilla and gonads after dissection. After measuring weight and length of young fish species, fish weighing 201-310 g were selected for the study. A total of 72 fish, eight and four fish per species and sexes were selected, respectively, for each site. The sample size was determined using “resource equation" method. Only edible fillet was labeled and transferred to plastic bags according to species and sex. Then the sample was transported for proximate analysis to Addis Ababa Food Science and Nutrition laboratory using icebox at about 4 °C. Fish sample composites were prepared by taking the fish samples from the three fish landing sites for each sex and species. Samples were thawed at room temperature and oven-dried at 60 °C for 72 h, then ground into a fine powder. Proximate composition was determined following the procedure of Association of Official Analytical Chemists (AOAC). Data analysis was conducted using analysis of variance (ANOVA). Nutrient content significantly varied among fish species; more protein was recorded from O. niloticus and fat from L. intermedius. Also, fat, ash and gross energy content were different between sexes; female fish contained significantly more fat and gross energy than males. In conclusion, consumers are advised to consume these species to obtain required nutrients.


Endocrinology ◽  
2020 ◽  
Vol 161 (6) ◽  
Author(s):  
Qifeng Zhang ◽  
Ding Ye ◽  
Houpeng Wang ◽  
Yaqing Wang ◽  
Wei Hu ◽  
...  

Abstract Androgen is essential for male development and cortisol is involved in reproduction in fishes. However, the in vivo roles of cortisol and specific androgens such as 11-ketotestosterone (11-KT) in reproductive development need to be described with genetic models. Zebrafish cyp11c1 encodes 11β-hydroxylase, which is essential for the biosynthesis of 11-KT and cortisol. In this study, we generated a zebrafish mutant of cyp11c1 (cyp11c1-/-) and utilized it to clarify the roles of 11-KT and cortisol in sexual development and reproduction. The cyp11c1-/- fish had smaller genital papilla and exhibited defective natural mating but possessed mature gametes and were found at a sex ratio comparable to the wildtype control. The cyp11c1-/- males showed delayed and prolonged juvenile ovary-to-testis transition and displayed defective spermatogenesis at adult stage, which could be rescued by treatment with 11-ketoandrostenedione (11-KA) at certain stages. Specifically, during testis development of cyp11c1-/- males, the expression of insl3, cyp17a1, and amh was significantly decreased, suggesting that 11-KT is essential for the development and function of Leydig cells and Sertoli cells. Further, spermatogenesis-related dmrt1 was subsequently downregulated, leading to insufficient spermatogenesis. The cyp11c1-/- females showed a reduction in egg spawning and a failure of in vitro germinal vesicle breakdown, which could be partially rescued by cortisol treatment. Taken together, our study reveals that zebrafish Cyp11c1 is not required for definite sex differentiation but is essential for juvenile ovary-to-testis transition, Leydig cell development, and spermatogenesis in males through 11-KT, and it is also involved in oocyte maturation and ovulation in females through cortisol.


Zootaxa ◽  
2019 ◽  
Vol 4702 (1) ◽  
pp. 32-40
Author(s):  
HSUAN-CHING HO

Pterophycis spatium gen. nov. et sp. nov. is described on the basis of two specimens collected from shallow waters of southwestern Taiwan. The new genus can be distinguished from other genera in the family in having genital papilla separated from anus by several small scales, all rays on pelvic fin elongate, and the following combination of characters: light organ present; snout broad and rounded, without shelf-like plate; teeth absent from palatines and vomer; swimbladder with anterior elongate projections that attached to openings at rear of the skull; pelvic fin with 7 rays; first dorsal fin short-based, with 8 rays; and second dorsal and anal fins long-based, their margins not indented. 


2019 ◽  
Vol 49 (3) ◽  
pp. 213-220
Author(s):  
Elisa Queiroz GARCIA ◽  
Jansen ZUANON

ABSTRACT Sexual dimorfism refers to morphological differences between males and females of a species. It may be a result of different selection pressures acting on either or both sexes and may occur in any sexually-reproducing dioecious species, including fishes. We analyzed 63 females and 63 adult males of Gymnorhamphichthys rondoni (Gymnotiformes) collected by us or deposited in museum collections. Sex was identified through abdominal dissection. We measured length from snout to posterior end of anal-fin, anal-fin length, distance from anus to anal-fin origin, distance from genital papilla to anal-fin origin, body width at beginning of anal-fin, and head length. Morphometric data submitted to a Principal Component Analysis (PCA) grouped males and females according to variables related to body size (along the first component) and to head length and body height along the second and third components. Females were larger than males, whereas males had proportionally larger heads and higher bodies than females. The urogenital papilla of males and females showed differences in shape, size and relative position on the body. The female papilla was elongated horizontally, larger than that of males, and was located on a vertical line below the eye, while the papilla of the males was vertically elongated and located on a vertical line below the operculum. To our knowledge, this is the first recorded case of sexual dimorphism in a species of Rhamphichthyidae, a condition that is now known in all the currently recognized families of Gymnotiformes.


Author(s):  
Néstor E. Ardila ◽  
Juan Manuel Díaz

A new species of the genus Armina,, collected off the northern Caribbean coast of Colombia at depths of 310 and 460 m in soft bottoms is described. The number of notal ridges, die position of the genital papilla, the size and the shape of radular teedi and the features of the masticator}' process arc the main differences to other congeneric spccies occurring in Atlantic waters. Armina juliana n. sp. is the first record for the family Arminidae in the Colombian Caribbean.


Nematology ◽  
2016 ◽  
Vol 18 (8) ◽  
pp. 949-962 ◽  
Author(s):  
Jiří Nermuť ◽  
Vladimír Půža ◽  
Zdeněk Mráček

A new nematode species belonging to the family Alloionematidae was originally isolated by Dr Marie Anne Félix on 16 December 2007 from a rotting coconut at the boat boarding point in Estuary island resort, Poovar, Kerala, India. Both morphologically and molecularly, the new isolate resembles Neoalloionema tricaudatum but, unlike N. tricaudatum this species has no phasmidial ‘horns’ in the juvenile stage, even though prominent structures in the mid-tail of dauer juveniles were observed. Females are characterised by a body length of 947 (869-1030) μm, vulva in the mid-body region, long, and tapering tail with a minute post-anal swelling. Males are 678 (606-757) μm long with a long tapering tail that is very thick at base. They are further characterised by seven pairs of genital papillae and a single genital papilla. Dauer juveniles are only 391 (364-434) μm long, thin and almost straight when heat-killed. Large, prominent phasmids are located laterally at the mid-tail region and lateral fields consisting of a single ridge are present. Several morphological and molecular differences encouraged us to describe the nematode as N. indicum n. sp. The ecology of the newly described species is unknown, but it is probably a saprophytic bacteriophagous nematode preferring rotting organic material.


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