ABSTRACT
Low molecular weight compounds: lactic acid, some amino acids, and acetylcholine iodide release a feeding response in hungry sea stars (Marthasterias glacialis). Single amino acids known from electrophysiological studies to stimulate fish chemoreceptors do not release feeding response when presented one at a time to naive brown-bullheads (Ictalurus nebulosus). Conditioning procedures established a single amino acid-food search association in the fish. Either single amino acids or mixtures of them can make-up a searching image in the fish. The second aim of this work is a comparison of behavioural data on chemoreception in Marthasterias glacialis with electrophvsiological data from structure-activity studies of chemoreceptors in the fishes Ictalurus nebulosus and Salmo gairdneri from the literature.
