LabEx Corail & ISEA, Université de la Nouvelle-Calédonie, BP R4, 98851, Nouméa cedex, New Caledonia.
Department of Biological Sciences, Macquarie University, NSW, 2109, Sydney, Australia.
Sci Rep. 2020 Jan 28;10(1):1377. doi: 10.1038/s41598-020-58258-2.
In defence of their nests or territories, damselfish (Pomacentridae) attack even large and potentially dangerous intruders. The Indo-Pacific region contains many species of sea snakes, some of which eat damselfish whereas others do not. Can the fishes identify which sea snake taxa pose a threat? We recorded responses of damselfishes to natural encounters with five species of snakes in two shallow bays near Noumea, New Caledonia. Attacks by fishes were performed mostly by demersal territorial species of damselfish, and were non-random with respect to the species, size, sex and colouration of the snakes involved. The most common target of attack was Emydocephalus annulatus, a specialist egg-eater that poses no danger to adult fishes. Individuals of a generalist predator (Aipysurus duboisii) that were melanic (and thus resembled E. annulatus in colour) attracted more attacks than did paler individuals. Larger faster-swimming snake species (Aipysurus laevis, Laticauda saintgironsi) were watched but not attacked, or were actively avoided (Hydrophis major), even though only one of these species (A. laevis) eats pomacentrids. Attacks were more common towards female snakes rather than males, likely reflecting slower swimming speeds in females. In summary, damselfishes distinguish between sea snake species using cues such as size, colour and behaviour, but the fishes sometimes make mistakes.
为了保卫巢穴或领地，雀鲷（Pomacentridae）甚至会攻击体型较大且可能具有威胁的入侵者。印度洋-太平洋地区有许多种海蛇，其中一些以雀鲷为食，而另一些则不然。这些鱼类能否识别出哪些海蛇类群构成威胁？我们记录了在新喀里多尼亚努美阿附近的两个浅湾中，五种蛇类与雀鲷自然相遇时雀鲷的反应。鱼类的攻击主要由底栖领地性雀鲷进行，并且与蛇的种类、大小、性别和颜色有关，并非随机发生。最常见的攻击目标是环纹蓑鮋（Emydocephalus annulatus），这是一种专门以卵为食的鱼类，对成年鱼类没有危险。具有体色的杂食性捕食者（Aipysurus duboisii）个体（与环纹蓑鮋颜色相似）比浅色个体吸引更多的攻击。体型较大、游动速度较快的蛇类（Aipysurus laevis、Laticauda saintgironsi）虽然只有一种（A. laevis）以雀鲷为食，但会被观察而不会被攻击，或者被主动避开（Hydrophis major）。即使如此，这些蛇类也会被观察而不会被攻击，或者被主动避开（Hydrophis major）。总的来说，雀鲷通过大小、颜色和行为等线索来区分海蛇物种，但有时也会犯错。
