In this study, morphological variations are established at the level of the carapace, pereopods, exognath of the third maxilliped and gonopod of 333 specimens of freshwater crabs of the species Neostrengeria charalensis from exo and endocarstic environments. The relationship of the length of the exognath to the ischium of the endognath of the third maxilliped presents an average of 0.55 for specimens of epigeal origin and 0.59 for hypogeal specimens. It was established that there are differences between the proportions of the total length of the second pereopod versus the width of the carapace, being greater this proportion in the specimens of hypogean habits in comparison to those with epigean habits. At the gonopod level, differences in cave specimens were described and illustrated. Relevant differences were found in morphological proportions, but these do not represent large variations. The importance of this study is that it allows us to conclude that there is an adaptive response by the specimens of hypogeous habits to their environment. Additionally, some aspects about the distribution, habitat and bioecology of this species in hypogeous environments are included.