The genetic mating system of a sea spider with male-biased sexual size dimorphism: evidence for paternity skew despite random mating success.

ABSTRACT: Male-biased size dimorphism is usually expected to evolve in taxa with intense male-male competition for mates, and it is hence associated with high variances in male mating success. Most species of pycnogonid sea spiders exhibit female-biased size dimorphism, and are notable among arthropods for having exclusive male parental care of embryos. Relatively little, however, is known about their natural history, breeding ecology, and mating systems. Here we first show that Ammothella biunguiculata, a small intertidal sea spider, exhibits male-biased size dimorphism. Moreover, we combine genetic parentage analysis with quantitative measures of sexual selection to show that male body size does not appear to be under directional selection. Simulations of random mating revealed that mate acquisiti

SUBMITTER: Barreto FS 

PROVIDER: S-EPMC3134710 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature