Brooding in Psolus patagonicus (Echinodermata: Holothuroidea) from Argentina, SW Atlantic Ocean

Abstract

The mode, season, and time of brooding, egg diameter, egg number per brood, and the characteristics of newly released juveniles of Psolus patagonicus were investigated off Mar del Plata, Buenos Aires, Argentina, between October 1999 and February 2001. Individuals were attached to the Patagonian scallop, Zygochlamys patagonica. Spawning occurs between February and March. The mean egg diameter, 887 ± 26 μm, is the highest reported for the family Psolidae. Eggs are brooded under the mother's sole until they develop into crawling juveniles within 7 months. The largest embryos reached a length of 1,941 ± 228 μm in September. During the brooding period (February-September) the number of brooded embryos decreased while their size increased. Our study confirms brooding behaviour in female P. patagonicus. © Springer-Verlag and AWI 2009.