First report of intersex in the signal crayfish Pacifastacus leniusculus (Dana, 1852)

Abstract

The reproductive strategies of species of non-indigenous crayfish make an important issue in astacological research. Although crayfish reproduction has been well studied, there is little information available on the occurrence of intersexuality. We report the first evidence of intersex in the signal crayfish, Pacifastacus leniusculus (Dana, 1852). An intersexual specimen was found among five tested signal crayfish. Morphology revealed both male and female genital openings, as well as male gonopods. The specimen superficially appeared male but contained both testes and ovaries, with an atypical dispersed structure. Sperm was obtained from this crayfish. Flistology showed both spermatocytes and oocytes. The gonadosomatic index (GSI = 3.79) was considered as a morphometric parameter of the intersexual crayfish. The ova present in the intersex male raised its GSI to the three-fold of that of normal males. RÉSUMÉLes stratégies de reproduction des espèces d'écrevisses non-indigènes constituent une question importante en recherche astacologique. Bien que la reproduction des écrevisses ait été bien étudiée, il y a peu d'information disponible sur la fréquence de l'intersexualité. Nous rapportons la première preuve d'un intersexué chez l'écrevisse Pacifastacus leniusculus (Dana, 1852). Un spécimen intersexué a été trouvé parmi les cinq écrevisses testées. La morphologie révèle les deux ouvertures génitales mâles et femelles, ainsi que des gonopodes de mâle. Le spécimen apparaît superficiellement mâle mais contient à la fois testicules et ovaires, avec une structure dispersée atypique. Du sperme a été obtenu de cette écrevisse. L'histologie montre à la fois des spermatocytes et des ovocytes. L'index gonadosomatique (GSI = 3,79) a été considéré comme un paramètre morphométrique de l'écrevisse intersexuée. Les ovules présents chez le mâle intersexué ont multiplié son GSI par trois par rapport à celui d'un mâle normal. ')

Different aspects of reproduction strategies in crayfish: A review

“…Rudolph (2002) collected intersexed specimens of S. spinifrons from rivers in Chile and in the description of a new species, Virilastacus rucapihulensis, Rudolph and Crandall (2005) note the presence of specimens with extra gonopores. Yazicioglu et al (2014) report the first evidence of intersex in the astacid signal crayfish, P. leniusculus (Fig. 1).…”

“…Among the Parastacidae, intersexuality has been determined in species from Oceania and South America. In the genus Parastacus of southern South America, simultaneous presence of male and (Yazicioglu et al, 2014).…”

0-15 Yaş Grubu Çocuğu Olan Ebeveynlerin Sosyodemografik Özellikleri ile COVID-19 Pandemi Döneminde Çocuk Diş Hekimliğine Olan Yaklaşımları ve Bilgi Düzeylerinin Kıyaslanması

“…23,24 Bilgili 15 , çalışmasında ebeveynlerin % 90.7'sinin çocuklarını herhangi bir yakınma olduğunda diş hekimine götürdüklerini belirttiklerini saptamıştır. Yazıcıoğlu ve ark 25 , benzer şekilde diş hekimine gitme nedeninin büyük çoğunlukla (% 94) bir yakınma sonucu olduğunu tespit etmişlerdir. Bu çalışmada pandemi döneminde çocuğunu diş hekimine götüren ebeveynlerin % 21.9'u ağrı şikayeti olduğunu, % 14.9'u pandemi dönemi öncesinde başlayan diş tedavilerine devam etmek için, % 14'ü yeni fark edilen bir çürüğün tedavisi için, % 11.4'ü kontrol maksatlı olduğu saptanmıştır.…”

Factors affecting the reproductive efficiency in crayfish: implications for aquaculture

“…Despite some cases of parthenogenesis and hermaphroditism (Rudolph ,b; Noro, López‐Greco & Buckup ; Buřič, Hulák, Kouba, Petrusek & Kozák ; Yazicioglu, Linhartova, Niksirat & Kozák ), crayfish have separate sexes (gonochoric) (Holdich ; Vogt ). Sex in crayfish can be recognized in early life stages by precursors of the gonopods (Harlıoğlu ).…”