Sexual size dimorphism and male reproductive traits vary across populations of a tropical rainforest dung beetle species ( Onthophagus babirussa ).

Autor: Toh KX; Department of Biological Sciences National University of Singapore Singapore Singapore., Yap S; Department of Biological Sciences National University of Singapore Singapore Singapore., Goh TG; Institute of Biological Sciences, Science Faculty University of Malaya Kuala Lumpur Malaysia., Puniamoorthy N; Department of Biological Sciences National University of Singapore Singapore Singapore.
Jazyk: angličtina
Zdroj: Ecology and evolution [Ecol Evol] 2022 Sep 16; Vol. 12 (9), pp. e9279. Date of Electronic Publication: 2022 Sep 16 (Print Publication: 2022).
DOI: 10.1002/ece3.9279
Abstrakt: Sexual size dimorphism (SSD) arises when natural selection and sexual selection act differently on males and females. Male-biased SSD is rarer in insects and usually indicates strong sexual selection pressure on male body size in a species. Patterns of SSD can also vary between populations of species that are exposed to different environmental conditions, such as differing resource availability and diversity. Here, we investigate intraspecific variation in SSD as well as relative investment in precopulatory (horn length) and postcopulatory traits (sperm length and testes weight) in a tropical rainforest dung beetle Onthophagus babirussa across Singapore and Peninsular Malaysia. Overall, three out of four populations displayed significant male-biased SSD, and SSD was greater in populations with smaller overall body size. Average male body size was similar across all populations while female body size was significantly smaller in Singapore, suggesting that the pronounced SSD may also be due to stronger sexual selection on male body size in Singapore populations. All populations showed significant investment in horns as a weapon likely used in male-male competition, while postcopulatory traits showed no clear scaling relationship with body size, suggesting a higher priority on precopulatory sexual traits in the mating system of this species.
Competing Interests: All authors certify that they have NO affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers' bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent‐licensing arrangements), or non‐financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
(© 2022 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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