Frye Marilena, Egeland Torvald B, Nordeide Jarle Tryti, Folstad Ivar
Faculty of Biosciences and Aquaculture Nord University Bodø Norway.
Faculty of Education and Arts Nord University Bodø Norway.
Ecol Evol. 2021 Sep 28;11(21):14383-14391. doi: 10.1002/ece3.8173. eCollection 2021 Nov.
From video recordings of spawning events, we quantified protective and cannibalistic behavior of Arctic charr occurring immediately after spawning. The number of fish cannibalizing on stray eggs was examined regarding (a) whether more than one male shed milt during the spawning event, that is, whether sperm competition occurred, (b) whether the sperm competition included few or many males, that is, the intensity of sperm competition, and (c) the density of fish at the spawning site. Response behavior toward egg cannibalism was also examined among females and dominant males in order to determine any parental investment toward protecting the eggs after spawning. Cannibalistic behavior was seen in almost 50% of the spawnings, and the multiple spawning events showed the highest numbers of fish cannibalizing on eggs. Both the number of males releasing milt and the number of fish approaching the spawning site were positively correlated with egg cannibalism. Sperm competition was, however, not a prerequisite for egg cannibalism. Although we also observed partial filial cannibalism, protective behavior of eggs was seen both among dominant males and females, suggesting that charr actually conduct parental care.
通过产卵事件的视频记录，我们量化了北极红点鲑在产卵后立即出现的保护行为和同类相食行为。我们研究了吞食散落鱼卵的鱼的数量与以下因素的关系：(a) 在产卵过程中是否有不止一只雄鱼排精，即是否发生精子竞争；(b) 精子竞争涉及的雄鱼数量少还是多，即精子竞争的强度；(c) 产卵地点的鱼的密度。我们还研究了雌鱼和优势雄鱼对卵同类相食的反应行为，以确定产卵后对保护鱼卵的任何亲代投资。在近50%的产卵过程中都观察到了同类相食行为，多次产卵事件中吞食鱼卵的鱼的数量最多。排精雄鱼的数量和靠近产卵地点的鱼的数量都与卵同类相食呈正相关。然而，精子竞争并不是卵同类相食的先决条件。虽然我们也观察到了部分子代同类相食现象，但在优势雄鱼和雌鱼中都观察到了对鱼卵的保护行为，这表明红点鲑实际上会进行亲代抚育。
