Abstract

Parents are sometimes confronted with information that suggests they are unrelated to the offspring under their care. When this happens, parents are expected to reduce their level of care into the offspring. However, studies have shown that this does not always happen. We use wild populations of plainfin midshipman fish to show that parents will reduce their level of care, though will only do so in response to certain types of information but not others.Effort spent on raising unrelated offspring can be costly and wasteful, and parents are expected to reduce their level of investment when they have low or uncertain relatedness to the young under their care. Although the relationship between parental certainty and parental investment is theoretically well established, empirical support has been mixed. Here, we report on a series of lab and field experiments that test whether paternal investment is reduced as paternity decreases in the plainfin midshipman fish (Porichthys notatus), a species of toadfish with male-only care. We explored what cues plainfin midshipman males use to assess their paternity. We show that a nest takeover, in which a male displaces another male from a nest, can be a reliable indirect cue of paternity information and leads to a drop in offspring survival. We also show that, when presented in isolation, direct cues of reduced offspring relatedness do not result in a decline in offspring survival in midshipman. Our findings help clarify what systems, species, and theoretical assumptions best reveal the link between parental investment and parentage.

Keywords

allocare; nest takeovers; offspring transplants; parentage; parental care; plainfin midshipman

Published in

Behavioral Ecology
2016, Volume: 27, number: 5, pages: 1507-1514
Publisher: OXFORD UNIV PRESS INC

UKÄ Subject classification

Behavioral Sciences Biology
Ecology


Publication identifier

DOI: https://doi.org/10.1093/beheco/arw075

Permanent link to this page (URI)

https://res.slu.se/id/publ/119492