tankmate

noun

tankmate

noun

Etymology From tank + -mate.

1

An aquarium fish that shares the same tank as another.

Dardanus megistios ^([sic]) pauses to consider the meaning of life as it chews the remains of a tankmate.2001, Julian Sprung, Invertebrates: A Quick Reference Guide, page 158:

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.