No evidence of predation causing female-biased sex ratios in marine pelagic copepods

Autor(es)

Mendes Gusmao, Luiz Felipe ^{[1, 2, 3, 4]} ; McKinnon, A. David ^[5] ; Richardson, Anthony J. ^{[2, 3]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ctr Biol Marinha CEBIMar, BR-11600000 Sao Sebastiao, SP - Brazil

^[2] Univ Queensland, Sch Math & Phys, Ctr Applicat Nat Resource Math, St Lucia, Qld 4067 - Australia

^[3] CSIRO Marine & Atmospher Res, Climate Adaptat Flagship, Ecosci Precinct, Dutton Pk, Qld 4102 - Australia

^[4] Univ Sao Paulo, Lab Plankton Syst, BR-11600000 Sao Sebastiao, SP - Brazil

^[5] Australian Inst Marine Sci, Townsville, Qld 4810 - Australia

• Tipo de documento: Artigo de Revisão
• Fonte: MARINE ECOLOGY-PROGRESS SERIES; v. 482, p. 279-298, 2013.
• Citações Web of Science: 15

Resumo

Although sex ratios close to unity are expected in dioecious species, biased sex ratios are common in nature. It is essential to understand causes of skewed sex ratios in situ, as they can lead to mate limitation and have implications for the success of natural populations. Femaleskewed sex ratios are commonly observed in copepods in situ. Here we discuss the challenges of copepod sex ratio research and provide a critical review of factors determining copepod sex ratios, focusing on 2 main objectives. The first is a critique of the male predation theory, which is currently the main process thought to be responsible for female-skewed sex ratios. It assumes that males have higher mortality because of increased vulnerability to predation during their search for mates. We show that there is little support for the male predation theory, that sex ratios skewed toward females occur in the absence of predation, that sex ratios are not related to predation pressure, and that where sex-skewed predation does occur, it is biased toward females. Our second objective is to suggest alternative hypotheses regarding the determination of sex ratios. We demonstrate that environmental factors, environmental sex determination and sex change have strong effects on copepod sex ratios, and suggest that differential physiological longevity of males and females may be more important in determining sex ratios than previously thought. We suggest that copepod sex ratios are the result of a mixture of factors. (AU)

• Processo FAPESP: 12/20322-0 - Avaliação da produção e condição do zooplâncton através de índices bioquímicos: Um estudo de caso na Baia do Araçá e Canal de São Sebastião
• Beneficiário: Luiz Felipe Mendes de Gusmão
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado