A number of Caribbean species of Tritonia were moved to a new genus Tritonicula in 2020 as a result of an integrative taxonomic study of the family Tritoniidae.

[2] Tritonicula hamnerorum is found in the Caribbean area with its range extending from the Gulf of Mexico to Curaçao and the Cayman Islands.

Background colour is translucent gray with a series of irregular, longitudinal, thin white lines that run along the length of the dorsum.

This in turn makes the nudibranch distasteful to predatory fish, such as the bluehead wrasse (Thalassoma bifasciatum), which avoid consuming this species.

On this occasion, 1,700 were found in a dense aggregation on one side of an area of sea fan measuring 0.27 square metres (2.9 sq ft).