Graduate School of Fisheries Science & Environmental Studies, Nagasaki University, Nagasaki, Japan.
J Fish Biol. 2013 Feb;82(2):475-91. doi: 10.1111/j.1095-8649.2012.03496.x. Epub 2012 Dec 28.
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.
现场和实验室研究考察了巢可用性和体型对暗鳍褶胸鱼雄性交配策略从偷偷摸摸到筑巢的变化的影响。在野外，巢持雄性的体型从繁殖季节早期到中期减小，表明偷偷摸摸雄性的策略可能发生变化。许多偷偷摸摸的雄性即使有空置的产卵巢可用，也不使用它们，而是继续作为偷偷摸摸的雄性繁殖。同样，在有可用空置巢的水族馆实验中，一些偷偷摸摸的雄性无论体型大小都成为了巢持雄性，但也有一些没有。这些结果表明，巢可用性不是该物种偷偷摸摸雄性改变策略的限制因素。由于在水箱中，未改变策略的偷偷摸摸雄性与体型较大的巢持雄性共同生活，附近巢持雄性的体型可能会影响偷偷摸摸雄性改变策略的决定。此外，改变策略的雄性中体型较小的个体往往需要更多的时间才能产卵，这可能是因为与体型较大的雄性相比，它们作为巢持雄性繁殖的相对成本更高，收益更小。
