Pre-Spawning Behavior in the Gobiid Fish, Bathygobius Soporator
Author: Tavolga, William N.
Source: Behaviour, Volume 9, Number 1, 1956 , pp. 53-73(21)
Abstract:The gobiid fish, Bathygobius soporator (Cuvier and Valenciennes), is a shallow water, tidal zone species with shelter-seeking, territorial habits. Males are particularly pugnacious toward each other, and exhibit a combat behavior which comprises a darkening of the coloration, fin erection, gaping, quivering, butting and biting. Prespawning behavior consists of (1) nest preparation, in which the male cleans out a shelter by fanning and scooping; (2) courtship - a light coloration with a blackened chin is exhibited by the male as he approaches a female and vibrates his body and tail; (3) nest entry - the female, if gravid, responds to the courtship by following the male and entering the nest. In spawning, the female extrudes adherent eggs on the inner surface of the nest, while the male releases sperm. After spawning, the male guards and fans the eggs for the 4 to 5 day incubation period. The establishment of a shelter and a territory by a male are necessary before coordinated pre-spawning behavior can take place. Females appear to exhibit less territoriality than males, and young males possess incompletely differentiated territorial, pre-spawning and spawning behavior patterns. In testing the reactions of resident males toward introduced animals, the tests had to be spaced in time sufficiently to avoid an overlapping of responses, because the reactions of the resident persist for some time after the removal of the intruder. The speed and type of reaction by the resident male could be influenced by rapid repetition of the tests. The first r e a c t i o n - c o m p l e x of the resident male toward an introduced animal comprises an approach to the intruder and, in many cases, is followed by or preceded by a color change. Frequently, especially with large males and gravid females as intruders, this reaction-complex shows a trend toward combat or courtship, respectively, before any activity on the part of the intruder. The responses of the introduced animals are varied but tend mostly toward retreat in small males and non-gravid females, combat in large males, and following in gravid females. The subsequent behavior of the resident shows a differentiation according to the sex, size and gonadal stage of the intruder. Combat is predominant towards large males, whereas courtship occurs toward gravid females. Sex discrimination by the resident male is variable, and the sensory cues involved are primarily behavioral in nature. It is thought that the intruding animal presents several visual cues (and possible non-visual ones), and these cues form a pattern which stimulates, channels and re-enforces, in that order, the behavior of the resident male.
Document Type: Research article
Publication date: 1956-01-01