Fecundity and Reproductive Output in Two Species of Deep-Sea Crabs, Geryon fenneri and G. quinquedens (Decapoda: Brachyura)

Publisher Website
Google Scholar
Abstract
Brood weight, fecundity, and egg size as a function of female body size were compared in the deep-sea red crab Geryon quinquedens and the deep-sea golden crab Geryon fenneri. Females of G. fenneri attained a larger body size than G. quinquedens, and body size in both species was the main determinant of reproductive output (brood mass) and fecundity per brood. Both species differed from most other brachyurans in having larger reproductive outputs, larger eggs, and lower fecundities relative to their large body sizes. After statistical adjustment for differences in body size between the two species, G. quinquedens had space in the body cavity for yolk accumulation and a brood mass which were 50% larger than T. fenneri. Geryon quinquedens, however, produced eggs 2.18 times the volume of G. fenneri, resulting in equivalent number of eggs per brood in similar-sized crabs. Large, yolky eggs in G. quinquedens are likely to contribute to the nutritional flexibility of its larvae, but apparently have coevolved with significant changes in female morphology and reproductive output.