MorphologyRead full entry
Sexual DimorphismMales often larger than females because females grow more slowly after maturity, but the reverse also occurs; dwarf males common in parasitic isopods (Bopyrus) and some species (e.g. Jaera) have both small and large males; male appendages often specialized for detecting pheromones, sexual signals, sperm transport or grasping females. Female appendages often modified for holding eggs. Color differences are common in crabs, shrimp and stomatopods.