Entry from British & World English dictionary
(plural same or pearlfishes)
1A long slender fish found chiefly in warmer seas, which lives inside the shells of bivalve molluscs or the body cavities of sea cucumbers and other invertebrates.
- Family Carapidae: several genera and species
2A small Argentinian killifish, popular in aquaria.
- Cynolebius belotti, family Cyprinodontidae
Definition of pearlfish in: