Species recognition and sex discrimination by males of the notchtongue goby, Bathygobius curacao (Pisces: Gobiidae)

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)


Marine Biology and Fisheries

First Committee Member

Arthur A. Jr. Myrberg - Committee Chair


A study on the sensory stimuli used by males of Bathygobius curacao to recognize conspecific females is presented. An ethogram of the reproductive and agonistic behavior of B. curacao revealed that it followed the typical gobiid reproductive pattern. During courtship, the male develops a distinctive color pattern, the courtship "mustache", which consists of a pale body, a black stripe across the cheek, black lips, and a horizontal black stripe through the eyes. Courting males are soniferous and these sounds appear to be produced by the forcible ejection of water from the buccal cavity. Playback experiments provided only minimal support for the hypothesis that these sounds are attractive to conspecific males. A series of experiments demonstrated that while the visual or chemical stimuli of conspecific females can induce courtship, the stimuli each differ in the degree of species- and sex-specific information they contain. Model-bottle experiments revealed that visual stimuli are of little value in differentiating conspecific females from heterospecifics, and had no value in sex discrimination. Such stimuli became more useful when the heterospecific diverged in form and color pattern from conspecific females. Temporarily depriving males of vision did not prevent successful spawning. Experiments with chemical stimuli demonstrated that both species recognition and sex discrimination are mediated primarily through the chemosensory system. Males differentiated between the chemical cues (pheromones) of conspecific females and those from the females of two other gobiid species. Pheromones from females elicited courtship when presented alone, while those from conspecific males elicited aggression, but only when presented simultaneously with visual stimuli. Males were able to evaluate the reproductive status of females, as stronger courtship was elicited by the pheromones of ovulated females relative to those from nonripe females. Females release pheromones in urine and from the ovaries and intestines, with urine being the primary source. Temporarily anosmic males failed to respond to these pheromones, demonstrating that they are detected by the olfactory system. Anosmic males continued to court ripe females and successfully spawned, indicating that the reproductive behavior of this species uses a complex of sensory stimuli.


Biology, Zoology; Agriculture, Fisheries and Aquaculture

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