Functional Evolution of Prolactin and Growth Hormone in Lower Vertebrates

Abstract

Some aspects of prolactin and growth hormone biology in fishes and amphibians are considered, including the nature of the secretory cells, the regulation of their activity, the chemistry of the hormones, and their physiological activity in relation to hydromineral metabolism and to growth and development. Inasmuch as most of the information is derived from only a small number of teleost and amphibian species, a broad evolutionary biology is difficult to derive without information from other fish groups especially, and a survey must be confined largely to a comparative biology of some representative higher bony fishes with some representative anurans and urodeles.