title: Tactic changes in dusky frillgoby Bathygobius fuscus sneaker males: effects of body size and nest availability.
abstract: Field and laboratory studies were conducted to examine the effects of nest availability and body size on changes in male mating tactics from sneaking to nest-holding in the dusky frillgoby Bathygobius fuscus. In the field, the body size of nest-holding males decreased from early to mid-breeding season, suggesting the possibility of a change in the tactics of sneaker males to nest-holding. Many sneaker males did not use vacant spawning nests even when size-matched nests were available, but they continued to reproduce as sneakers. Similarly, in aquarium experiments with available vacant nests, some sneaker males became nest-holders irrespective of their body size, but some did not. These results showed that nest availability is not a limiting factor for changes in tactics by sneaker males in this species. Because tactic-unchanged sneaker males were co-housed with larger nest-holding males in the tanks, the body size of nearby nest-holding males may have affected the decision to change tactics for sneaker males. Moreover, smaller individuals among tactic-changed males tended to spend more time until spawning, probably because they had relatively larger costs and smaller benefits of reproduction as nest-holding males compared to larger males.
authors: Graduate School of Fisheries Science & Environmental Studies, Nagasaki University, Nagasaki, Japan. takegaki@nagasaki-u.ac.jp
authors: T
authors: T
authors: Takegaki
authors: T
authors: T
authors: Kaneko
authors: Y
authors: Y
authors: Matsumoto
mesh_terms: D000818:Animals; D049628:Body Size / Q000502:physiology*; D005260:Female; D008297:Male; D010473:Perciformes / Q000033:anatomy & histology* / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*