A Novel Association between Larval and Juvenile Erythrocles schlegelii (Teleostei: Emmelichthyidae) and Pelagic Tunicates
We describe the first documented associations between an emmelichthyid and a pelagic tunicate. An in situ observation of larval and juvenile Japanese Rubyfish, Erythrocles schlegelii (Emmelichthyidae) was made during blackwater scuba dives in the epipelagic waters off the coast of the Philippines. The fish were in close association with the pelagic salp Pegea confoederata (Thaliacea; Salpidae), either drifting alongside a colony of salps or residing inside individual salp cavities. Our results describe and illustrate this behavior, highlighting a previously undocumented family of fishes that associates with pelagic gelatinous invertebrates. This finding also demonstrates the importance of community science to further our understanding of the early life history of marine fishes.

The emmelichthyid Erythrocles schlegelii inside salps. (A) Larvae, November 13, 2021; (B) larvae, December 26, 2018; (C) juvenile, March 16, 2020. All photos by M. Bartick.
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