Dual function and associated costs of a highly exaggerated trait in a cichlid fish
| Autor: | Nidal Karagic, Sina J. Rometsch, Gonzalo Machado-Schiaffino, Axel Meyer, Julián Torres-Dowdall |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Amphilophus citrinellus
secondary sexual characteristic Ecology biology ornament Secondary sex characteristic Zoology biology.organism_classification Amphilophus citrinellus armament dual signaling Midas cichlids ornament secondary sexual characteristic sexual selection Cichlid ddc:570 Sexual selection dual signaling Trait sexual selection Fish Midas cichlids QH540-549.5 Research Articles Ecology Evolution Behavior and Systematics Dual function Research Article armament Nature and Landscape Conservation |
| Zdroj: | Scopus Ecology and Evolution Ecology and Evolution, Vol 11, Iss 23, Pp 17496-17508 (2021) RUO. Repositorio Institucional de la Universidad de Oviedo instname |
| Popis: | Exaggerated secondary sexual characteristics are apparently costly and seem to defy natural selection. This conundrum promoted the theory of sexual selection. Accordingly, exaggerated secondary sexual characteristics might be ornaments on which female choice is based and/or armaments used during male–male competition. Males of many cichlid fish species, including the adaptive radiation of Nicaraguan Midas cichlids, develop a highly exaggerated nuchal hump, which is thought to be a sexually selected trait. To test this hypothesis, we conducted a series of behavioral assays in F2 hybrids obtained from crossing a species with a relatively small hump and one with an exaggerated hump. Mate‐choice experiments showed a clear female preference for males with large humps. In an open‐choice experiment with limited territories, couples including large humped males were more successful in acquiring these territories. Therefore, nuchal humps appear to serve dual functions as an ornament for attracting mates and as an armament for direct contest with rivals. Although being beneficial in terms of sexual selection, this trait also imposes fitness costs on males possessing disproportionally large nuchal humps since they exhibit decreased endurance and increased energetic costs when swimming. We conclude that these costs illustrate trade‐offs associated with large hump size between sexual and natural selection, which causes the latter to limit further exaggeration of this spectacular male trait. Exaggerated secondary sexual characteristics might be ornaments on which female choice is based and/or armaments used during male–male competition, but at the same time, such traits are often costly. Here, we find that exaggerated head humps in Midas cichlids confer dual functions as an ornament for attracting mates and as an armament for contest with rivals, while also imposing fitness costs regarding swimming performance. We conclude that these costs illustrate trade‐offs associated with large hump size between sexual and natural selection, which causes the latter to limit further exaggeration of this spectacular male trait. |
| Databáze: | OpenAIRE |
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