Reproductive patterns of gammaridean amphipods

Patterns of reproductive parameters found among the gammaridean amphipod crustaceans were examined quantitatively. Highly significant positive correlations were found in pairwise comparisons of brood size, egg size, minimum size of reproductive females, and mean size of reproductive females. Significantly higher values of minimum and mean size of reproductive females and brood size were found for comparisons of: I) winter versus summer populations of the same amphipod species, 2) brackish-water versus freshwater and marine species, 3) species of the family Gammaridae versus the families Ampeliscidae and Haustoriidae, 4) single-brooded versus multiple-brooded species (brood size only), and 5) infaunal versus epifaunal species. Reproductive patterns app ear to be more specific within amphipod family groupings than is true for some other organisms, potentially because of the habit at specificity of the gammaridean families examined.