Parental fish change their cannibalistic behaviour in response to the cost-to-benefit ratio of parental care
Partial filial cannibalism, the act of cannibalizing some offspring, has been explained as a response to the high energetic cost of care. I tested this hypothesis by manipulating the cost-to-benefit ratio of care in the scissortail sergeant, Abudefduf sexfasciatus, a tropical damselfish with male...
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier Ltd.
2004
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| Online Access: | http://ir.unimas.my/id/eprint/17593/ http://ir.unimas.my/id/eprint/17593/1/Parental%20fish%20change%20their%20cannibalistic%20behaviour%20in%20response%20%28abstract%29.pdf |
| Summary: | Partial filial cannibalism, the act of cannibalizing some offspring, has been explained as a response to the
high energetic cost of care. I tested this hypothesis by manipulating the cost-to-benefit ratio of care in the
scissortail sergeant, Abudefduf sexfasciatus, a tropical damselfish with male care. Background egg mortality
was lower than the incidence of cannibalism, confirming that males did not just dispose of dead eggs.
Investment in the current brood affected future investment, because males forced to skip a brood cycle put
more effort into courtship during the following cycle and obtained larger broods than did unmanipulated
males. Any factor influencing the cost-to-benefit ratio of parental care should also affect the incidence of
cannibalism. I reduced the cost of care by supplementary feeding and reduced the benefit of care by
simulating a decrease in paternity certainty through simulated intrusions by non-nesting males.
Supplementary feeding significantly reduced partial filial cannibalism by parental males, a result
compatible with the hypothesis that eggs are consumed to cover the energetic costs of parental care.
Cannibalism decreased regardless of whether males were fed with conspecific eggs or crabmeat.
Cannibalism was only reduced but not fully eliminated by supplementary feeding, and residual levels
of cannibalism after feeding were similar to the background rate of egg mortality. Simulated intrusions by
non-nesting males led to an increase in filial cannibalism and a decrease in parental effort. |
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