The phylogeny of parental care in fishes

This paper tests the hypothesis that in the evolution of parental care, taxa of bony fish should only exhibit certain transitional states (where a transition is defined by the occurrence of at least two types of parental care within a genus or family). These are those between no parental care and male care, male care and biparental care, biparental care and female care, and female care and no parental care. A review of the teleost literature reveals 21 transitions. All of these agree with the hypothesized transitions and, in some cases, the direction of evolution is inferred by simple pedigree analysis.