Aplexa rivalis is a species of small air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Physidae, a family which are sometimes known as the bladder snails.

Rivalis Aplexa has a thin shell levorotatory, featuring a large oval opening with parietal callus lip sharp and wide.

The tentacles are filiform and foot is very long in the back.

[1] This species occurs in: Chaetogaster limnaei and Nais communis were found to be associated with Aplexa rivalis in Brazil.

[2] In Venezuela it is found inhabiting ornamental ponds in the leaves of plants and vegetable crops, and are common in aquarium shops.