[2] P. ananas has the widest distribution among the species of the genus, occurring throughout lowlands in entire Amazon (including Rio Negro) and Essequibo River basins.

[2] Physopyxis species are usually found in places with accumulated organic debris, like dense meshes of roots of floating macrophytes that are abundant in rivers with turbid water or submerged litter banks.

Specimens also can be found among submerged leaf litter and among root mats of riparian plants, like Symmeria paniculata (Polygonaceae).

P. lyra is predominantly nocturnal, and spends most of day time sheltered among submersed root mats or buried in sand.

[2] P. ananas and P. lyra have been found together among the submerged roots of aquatic macrophytes (Paspallum repens, Poaceae) at Amanã Lake, Japurá River basin.