Mucus provisioning behavior in teleost fishes: a novel model system for the evolution of secretory provisioning in vertebrates

Abstract

Across teleost fishes, a wide range of parental care strategies have been observed. However, despite this large variation in parental care behaviors, postnatal nutritional provisioning has rarely been documented in fishes. In other taxa, anecdotal evidence suggests that nutritional provisioning of offspring via mucus secretion by parents may occur, although this phenomenon has received little attention from evolutionary biologists, especially in fishes. To address this knowledge gap, we investigate the intra- and interspecific differences, functions, and the costs and benefits of provisioning behaviors that have potentially evolved independently in different teleost clades. Furthermore, we review and discuss within an ecological and evolutionary context, the anecdotal reports and limited available empirical evidence that shows support for mucus provisioning in teleost fishes.