The post-marsupial growth stages of the gammaridean ampithoid species Sunampithoe pelagica Milne-Edwards, 1830, six developmental stages for juveniles, three for females and at least seven for males, were described. The characterization was based on the increase of antennal article number, in the morphological modifications of gnathopods I and II, and on alteration of the number of setae.
Ampithoidae; Sunampithoe pelagica; morphological alterations; growth stages
