INTERSEXUALITY IN THE BURROWING CRAYFISH PARASTACUS VARICOSUS FAXON, 1898 (DECAPODA, PARASTACIDAE)

Autor: Erich H. Rudolph, Julia Tapia, Ana Verdi
Rok vydání: 2001
Předmět:
Zdroj: Crustaceana. 74:27-37
ISSN: 1568-5403
DOI: 10.1163/156854001505415
Popis: [The problem of intersexuality was studied in the burrowing crayfish, Parastacus varicosus, by examining sexual characters of 142 specimens from Uruguay. It was demonstrated that all specimens had supernumerary gonopores, with a masculine or feminine gonad, from which gonoducts of both sexes emerged toward the respective gonopores. Under 22.6 mm of standard cephalothoracic length (SCL), all specimens (N = 105) had the same external morphology. However, dissection showed that their gonads were already differentiated, and it was found that 57.1% of the specimens were intersex females and the remaining percentage were intersex males. Thirty-seven individuals with a SCL equal or superior to 22.6 mm were found. Of these, 14 (37.8%) were intersex males, and presented the same external morphology that characterized the specimens of sizes under 22.6 mm. The remaining 23 specimens (62.2%) were intersex females, nine of which presented the secondary sexual characters associated with egg incubation. A possible explanation for this type of intersexuality is given. Se estudio el problema de la intersexualidad en el camaron excavador Parastacus varicosus, a traves del examen de los caracteres sexuales de 142 ejemplares capturados en Uruguay. Se demostro que todos los especimenes tienen gonoporos supernumerarios, con una gonada masculina o femenina de la cual surgen gonoductos de ambos sexos hacia los respectivos gonoporos. Bajo los 22,6 mm de longitud estandar del cefalotorax (LEC), todos los ejemplares (N = 105) tienen la misma morfologia externa. Sin embargo, las disecciones demostraron que sus gonadas ya estaban diferenciadas, encontrandose que el 57,1% de los ejemplares eran hembras intersexo y el porcentaje restante, machos intersexo. Se encontraron 37 individuos de LEC igual o superior a 22,6 mm. De ellos, 14 (37,8%) eran machos intersexo, los que presentaban la misma morfologia externa que caracteriza a los ejemplares de tallas inferiores a 22,6 mm. Los restantes 23 (62,2%) eran hembras intersexo, en 9 de las cuales se comprobo la presencia de caracteres sexuales secundarios asociados a la incubacion de los huevos. Se propone una probable explicacion para este tipo de intersexualidad., The problem of intersexuality was studied in the burrowing crayfish, Parastacus varicosus, by examining sexual characters of 142 specimens from Uruguay. It was demonstrated that all specimens had supernumerary gonopores, with a masculine or feminine gonad, from which gonoducts of both sexes emerged toward the respective gonopores. Under 22.6 mm of standard cephalothoracic length (SCL), all specimens (N = 105) had the same external morphology. However, dissection showed that their gonads were already differentiated, and it was found that 57.1% of the specimens were intersex females and the remaining percentage were intersex males. Thirty-seven individuals with a SCL equal or superior to 22.6 mm were found. Of these, 14 (37.8%) were intersex males, and presented the same external morphology that characterized the specimens of sizes under 22.6 mm. The remaining 23 specimens (62.2%) were intersex females, nine of which presented the secondary sexual characters associated with egg incubation. A possible explanation for this type of intersexuality is given. Se estudio el problema de la intersexualidad en el camaron excavador Parastacus varicosus, a traves del examen de los caracteres sexuales de 142 ejemplares capturados en Uruguay. Se demostro que todos los especimenes tienen gonoporos supernumerarios, con una gonada masculina o femenina de la cual surgen gonoductos de ambos sexos hacia los respectivos gonoporos. Bajo los 22,6 mm de longitud estandar del cefalotorax (LEC), todos los ejemplares (N = 105) tienen la misma morfologia externa. Sin embargo, las disecciones demostraron que sus gonadas ya estaban diferenciadas, encontrandose que el 57,1% de los ejemplares eran hembras intersexo y el porcentaje restante, machos intersexo. Se encontraron 37 individuos de LEC igual o superior a 22,6 mm. De ellos, 14 (37,8%) eran machos intersexo, los que presentaban la misma morfologia externa que caracteriza a los ejemplares de tallas inferiores a 22,6 mm. Los restantes 23 (62,2%) eran hembras intersexo, en 9 de las cuales se comprobo la presencia de caracteres sexuales secundarios asociados a la incubacion de los huevos. Se propone una probable explicacion para este tipo de intersexualidad.]
Databáze: OpenAIRE