This snail is known around the South African coast from the Cape Peninsula to Coffee Bay in depths of 8–30 m. This species is endemic to the area.

[1] Triviella ovulata has a plump, round, white to deep pink shell.

In life the shell is usually completely covered with the white mantle, which is variably spotted with black.

The snail first drills a hole in the wall of the colony, then eats its fill and finally lays its capsule-shaped egg cases in the resulting cavity.

The black-spotted form of this animal resembles Mandela's nudibranch, Mandelia mirocornata, which may cause fish predators to avoid it.