title: The role of chemical and visual stimuli in the preferential discrimination of young by the cichlid fish cicblasoma nigrofasciatum (günther).
abstract: During the parental period, females of the cichlid fish Cichlasoma nigrofasciatum have demonstrated a keen ability to locate and preferentially discriminate their own wiggling young from those of other species on the basis of chemoreception. Males also apparently perceive chemical substances emitted by their young, but their response is weak in comparison to that of the female. There was no apparent perception of chemical substances emanating from eggs until 10 to 15 hours prior to hatching at which time, females began responding to them. No clear nor consistent preference by visual means, alone was shown by pairs of C. nigrofasciatum toward wiggling young of either their own species or those of Hemichromis; however, rapid preferential discrimination, by such means, was shown when a pair's own wiggling young were tested with free-swimming young of a foreign species. Vision apparently serves primarily for orienting the parents to young during their wiggling stage of development, while chemoreception serves primarily a discriminative function, at least, when both chemical and visual  stimuli are present in a given situation. Once the free-swimming stage of development has been reached, parental vision not only continues to mediate orientation to the young, but also assumes an increasing role in discriminating among different  types of young. When combining the chemical stimuli of wiggling young of their own species with the visual stimuli of either these same young or wiggling young of another species, females of C. nigrofasciatum apparently can learn, within 15 to 19 hours, sufficient visual characteristics to show preferential discrimination, at least, for a period of 5 to 7 hours after removal of the chemical stimuli. This result was in sharp contrast to that seen when visual stimuli, alone were tested for the same or longer periods. The interaction of chemical and visual stimuli in young recognition by parental cichlids and the relevance of the present findings to previous studies, dealing with similar mechanisms, are discussed.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology*; D005260:Female; D005399:Fishes / Q000502:physiology*; D008297:Male; D008425:Maternal Behavior; D010332:Paternal Behavior; D010675:Pheromones / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
chemical_list: D010675:Pheromones