Dwarfs or giants? Sexual size dimorphism in chondracanthidae (Copepoda, Poecilostomatoida)

Abstract

Sexual size dimorphism in the Chondracanthidae is very marked: we investigate whether it is a consequence of dwarfing of males or females becoming giants. Plotting male size against female size indicates that the relationship is allometric, i.e., showing a trend towards increasing sexual size dimorphism. This is supported by the results of an analysis of sexual size dimorphism against morphological distance, although not significant when phylogeny is controlled for. It appears that both sexes are driving the sexual size dimorphism, and chondracanthid females are probably selected for high fecundity leading to large body size, whereas males are probably selected for small size. © Koninklijke Brill NV, 2005.