Axial gynandromorphy and sex determination in Branchinecta lindahli (Branchiopoda: Anostraca)

In the Crustacea, sex determination is generally considered to be cell non-autonomous, with a centralized sex differentiation signaling system. However, observed frequencies of axial (anterior-posterior) morphological gynandromorphs of Branchinecta lindahli Packard, 1883 suggest cell autonomous sex determination. Thoracic appendages of seven Branchinecta lindahli axial gynandromorphs with male second antennae and female genitalia were compared to normal male and female thoracic appendages to quantitatively determine if the putative gynandromorphs showed evidence of intersexuality. None of the gynandromorphs showed evidence of intersexuality, supporting the occurrence of cell autonomous sex determination in branchiopod crustaceans.