Intersexualidad en el camarón excavador Parastacus pugnax (Poeppig, 1835) (Decapoda, Parastacidae)

Abstract

The problem of intersexuality was studied in the burrowing crayfish Parastacus pugnax (Poeppig, 1835) by examination of sexual characters of 538 specimens captured in Nehuentúe, Chile. It was demostrated that in this species both male and female are intersex, with supernumerary gonopores and with single gonad -either male or female- from which emerge gonoducts of both sexes to the respective gonopores. In males the oviducts are rudimentary and female gonopores are semiellipsoidal, with a very calcified cover. In females the sperm ducts are rudimentary and female gonopores are ellipsoidal and covered by a noncalcified membrane or just partially calcified. Permanent secondary sexual characters associated with incubation of eggs were identified in females. The adaptive value of this type of genitalia is discussed in the evolutionary historical context of Parastacidae.