Intersexuality in the mysid Neomysis integer

Abstract

Intersexuality is described in Neomysis integer (Leach), apparently the first occurrence among the Mysidacea. Seven out of 13,700 specimens examined were masculinized females possessing elongated fourth pleopods, a male secondary sexual characteristic. Each masculinized female appeared to have reproduced as a normal female; there was no evidence of testicular tissue.

Intersexuality in the porcellanid crab Pisidia longicornis (Crustacea: Decapoda: Anomura: Porcellanidae)

“…Different hypotheses have been suggested to explain intersexuality in crustaceans, including parasitism (NIELSEN 1970, GINSBURGER-VOGEL 1991, genetic abnormalities (HOUGH et al 1992), environmental contamination (OLMSTEAD & LEBLANC 2007, MAZUROVÁ et al 2010, FORD 2012 and social organization (TÓTH & BAUER 2008). Since no bopyrid or rhizocephalan parasites were found associated with intersex Pisidia longicornis individuals, and no abnormalities were found on their carapace, pereopods, abdomen or pleopods, it is unlikely that macro-parasites are the cause of intersexuality in these crabs.…”

Simultaneous activity of male and female gonads in intersex hermit crabs

“…Among invertebrates, molluscs show a similar phenomenon termed 'imposex', which is related to tributyltin (TBT) contamination (Gibbs et al 1991, Bettin et al 1996, Rank 2009). Crustacean intersexuality has been associated with natural events, such as viral infection (Juchault et al 1991), parasites (Ginsburger-Vogel 1991, hereditary factors including genetic abnormalities (Hough et al 1992), social (demographic) structure (Baeza & Bauer 2004), and abiotic factors (Bauer 2002).…”

Aberrant individuals ofNeomysis integer and other Mysidacea: Intersexuality and variable telson morphology

“…Intersexuality is a common phenomenon among species of other orders of peracaridan crustaceans. It has previously also been reported in representatives of the Isopoda, the Tanaidacea and the Amphipoda (HOUGH et aL, 1992).…”

“…It is a hyperbenthic, euryhaline and eurythermic species, typically occurring in high numbers in estuarine, brackish water environments (TATIERSALL and TATTERSALL, 1951). HOUGH et al (1992) reported intersexual individuals of this species, Le. animals which display both male and female secondary sexual traits, from the Conwy estuary (north Wales).…”

“…The other 2 individuals displayed a similar regeneration pattern. HOUGH et al (1992) claim that their records of intersexual individuals of Neomysis integer in the Conwy estuary are the first occurrences among the Mysidacea. This is not the case.…”