Pregnant pipefish with a simple brooding surface loose less weight when carrying heavier eggs: evidence of compensation for low oocyte quality?
- 130 Downloads
The evolutionary radiation of syngnathids has been accompanied by a diversification of structures involved in parental care, from a hypothetical ancestral presenting a simple brooding structure. The architectural simplicity of Nerophis male brooding structures led to the hypothesis that the relationship between father and developing embryos was feeble, unlike that observed in syngnathids with brood pouches. Here, we show that males loose considerable weight during pregnancy, especially so when egg weight is low. These results highlight the possibility of a compensatory mechanism and help justify why males in the wild tend to select large and colourful females, which are more fecund and able to produce larger eggs. Together with available information on the mating system, we also discuss some of the interplaying reasons behind the observed sex role reversal and high sexual dimorphism in the worm pipefish.
KeywordsDifferential allocation Pregnancy Sexual dimorphism Embryonic development Sexual selection
The Portuguese Foundation for Science and Technology funded Nuno Monteiro through a postdoc grant (SFRH/BPD/103829/2014). We thank the contribution of Clara Amorim, Anders Berglund and an anonymous reviewer, which helped improve the manuscript.
- Berglund A, Rosenqvist G, Svensson I (1986) Reversed sex-roles and parental energy investment in zygotes of 2 pipefish (Syngnathidae) species marine ecology progress series. 29:209–215. doi: 10.3354/meps029209
- Herald ES (1959) From pipefish to seahorse: a study of phylogenetic relationships. Proc Natl Acad Sci USA 29:465–473Google Scholar
- Lahaye J (1971) L'Ovogenèse chez Nerophis lumbriciformis (Pennant, 1776). Le cycle sexuel Cahiers De Biologie Marine 12:239–254Google Scholar
- Monteiro NM, Lyons DO (2012) Stronger sexual selection in warmer waters: the case of a sex role reversed pipefish. PLoS ONE 7. doi: 10.1371/journal.pone.0044251
- Monteiro N, Silva R, Cunha M, Antunes A, Jones A, Vieira M (2013a) Validating the use of coloration patterns for individual recognition in the worm pipefish using a novel set of microsatellite markers. Mol Ecol ResourGoogle Scholar
- Monteiro N, Vieira M, Lyons D (2013b) Operational sex ratio, reproductive costs, and the potential for intrasexual competition. Biol J Linn SocGoogle Scholar
- Monteiro N, Carneiro D, Antunes A, Queiros N, Vieira N, Jones A (2017a) The lek mating system of the worm pipefish (Nerophis lumbriciformis): a molecular maternity analysis and test of the phenotype-linked fertility hypothesis. Mol Ecol 26:1371–1385. doi: 10.1111/mec.13931 CrossRefPubMedGoogle Scholar
- Monteiro N, Cunha M, Ferreira L, Vieira N, Antunes A, Lyons D, Jones AG (2017b) Parabolic variation in sexual selection intensity across the range of a cold-water pipefish: implications for susceptibility to climate change. Glob Chang Biol. doi: 10.1111/gcb.13630
- Ripley J (2009) Osmoregulatory role of the paternal brood pouch for two Syngnathus species. Comp Biochem PhysiolGoogle Scholar
- Stolting K, Wilson A (2007) Male pregnancy in seahorses and pipefish: beyond the mammalian model BioEssays 29Google Scholar