Potamocypris unicaudata is a species of ostracod crustacean in the family Cyprididae, subfamily Cypridopsinae.

[1] The carapace of P. unicaudata is sub-reniform in shape and laterally compressed.

In the scanning electron microscope, at magnifications of 500 x and above, tiny pits become visible.

The second antennae carry swimming setae distinctly extending beyond the tips of the terminal claws.

[2] No males of P. unicaudata have so far been found and it is therefore inferred that the species reproduces parthenogenetically.