ABSTRACT
The isolation and characterization of the salmfamide neuropeptides from various species of asteroid, echinoid and holothuroid has heralded a new era of research in echinoderm biology. An extensive network of immunoreactive fibres is also evident throughout the basic epithelial plexus of the alimentary canal and in association with putative gut neuroendocrine cells. The apical muscle, skin and tube feet all contain strongly immunoreactive neuronal networks. The extensive neuronal and endocrine distribution of these peptides in echinoids and asteroids makes them strong candidate regulatory molecules for a wide range of physiological processes. Present morphological evidence suggests a role in sensory networks for while preliminary bioassay in asteroids implicates as a powerful regulator of stomach relaxation.
