Cannibalism and protective behavior of eggs in Arctic charr (Salvelinus alpinus)

Abstract

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.

Genetic compatibility exceeds possible ‘good genes’ effects of sexual selection in lake char

“…This supports analogous results from other salmonids [4]. It is possible that females benefit from the protection that dominant males sometimes provide against egg predation during the first minutes after spawning [65,66] or from higher fertilization success due to milt and sperm traits linked to male dominance [43,67]. However, if females aim for genetic benefits, we conclude from our results that they prefer genetically dissimilar males with whom they would produce offspring of low inbreeding coefficients.…”

Genetic compatibility exceeds possible ‘good genes' effects of sexual selection in lake char

“…This supports analogous results from another salmonid (Jacob et al 2007). It is possible that females bene t from the protection that dominant males sometimes provide against egg predation during the rst minutes after spawning (Frye et al 2021) or from higher fertilization success due to milt and sperm traits linked to male dominance (Masvaer et al 2004;Nusbaumer et al 2023). However, if females aim for genetic bene ts, we predict from our results that they prefer genetically dissimilar males with whom they would produce offspring of low inbreeding coe cients.…”

Nunavik anadromous Arctic char life histories, behaviour, and habitat use informed by both Inuit knowledge and western science: a year in Ungava Bay

“…A protective behaviour towards the eggs was observed by Frye et al (2021) who also documented cannibalism on the eggs, increasing with male competition. Cannibalistic behaviour on the eggs was not mentioned by participants.…”