Post-copulatory sexual selection and sexual conflict in the evolution of male pregnancy

  title={Post-copulatory sexual selection and sexual conflict in the evolution of male pregnancy},
  author={K A Paczolt and Adam G. Jones},
Male pregnancy in seahorses, pipefishes and sea dragons (family Syngnathidae) represents a striking reproductive adaptation that has shaped the evolution of behaviour and morphology in this group of fishes. In many syngnathid species, males brood their offspring in a specialized pouch, which presumably evolved to facilitate male parental care. However, an unexplored possibility is that brood pouch evolution was partly shaped by parent–offspring or sexual conflict, processes that would result in… 
Postcopulatory Sexual Selection and the Evolution of Male Pregnancy in the Gulf Pipefish
The data suggests that male Gulf pipefish sacrifice investment in future reproduction, via somatic growth, in favor of current reproduction, and a relationship between number of failed eggs and male growth rate in low-food tr ea ments suggests that males may derive an energetic benefit from unsuccessful eggs in the brood pouch.
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The concept of post-copulatory sexual selection is a powerful heuristic tool to explain variation in individual fitness and the staggering variation in sexual strategies both across and within species.
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Sexual selection on female ornaments in the sex‐role‐reversed Gulf pipefish (Syngnathus scovelli)
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The taxonomic distribution of syngnathid parity mode is assayed, the selective pressures that may have led to the emergence of male pregnancy are examined, the biology of synathids reproduction is described, and pressing areas for future research are highlighted.
Genetic evidence for polygynandry in the black-striped pipefish Syngnathus abaster: a microsatellite-based parentage analysis.
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The Effects of Food Limitation on Life History Tradeoffs in Pregnant Male Gulf Pipefish
Monitoring growth rate and offspring survivorship during the pregnancies of males under low- or high-food conditions suggests that undeveloped eggs reduce the pregnancy’s overall cost to the male compared to broods containing only viable offspring.
Sexual conflict in Gerris gillettei (Insecta: Hemiptera): influence of effective mating rate and morphology on reproductive success
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A DNA–based study of parentage in the Gulf pipefish Syngnathus scovelli is used to show that sexual selection indeed acts more strongly on females than on males in this species, and exhibits classical polyandry with the greatest asymmetry in reproductive roles yet documented in any system.
The Bateman gradient and the cause of sexual selection in a sex–role–reversed pipefish
It is shown that, in the male–pregnant pipefish Syngnathus typhle, females exhibit a stronger positive association between number of mates and fertility than do males and that this relationship responds in the predicted fashion to changes in the adult sex ratio.
The effect of perceived female parasite load on post-copulatory male choice in a sex-role-reversed pipefish
Overall, the results show that potential for post-copulatory sexual selection does exist in pipefish, but the male’s perception of female parasite load does not play a major role in this process.
Mate choice, fecundity and sexual dimorphism in two pipefish species (Syngnathidae)
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Microsatellite analysis of maternity and the mating system in the Gulf pipefish Syngnathus scovelli, a species with male pregnancy and sex‐role reversal
Highly variable microsatellite loci were employed to study the mating system of the sexually dimorphic Gulf pipefish Syngnathus scovelli, and it was determined that only one male had received eggs from more than a single female; and on two separate occasions, two different males had receiving eggs from the same female.
Male pregnancy in seahorses and pipefish: beyond the mammalian model
Understanding the changes associated with the parallel evolution of male pregnancy in the two major syngnathid lineages will help to identify key innovations that facilitated the development of this unique form of reproduction and, through comparison with other forms of live bearing, may allow the identification of a common set of characteristics shared by all viviparous organisms.
Male mate choice, sexual conflict and strategic allocation of copulations in a lekking bird
It is concluded that choosiness may sometimes pay for popular males in those lekking species where females copulate repeatedly, and evolutionary conflicts of interest between individuals may cause a richer repertoire of behavioural adaptations than, to the authors' knowledge, hitherto realized.
Reproductive mode and speciation: the viviparity-driven conflict hypothesis.
  • D. W. Zeh, J. A. Zeh
  • Biology
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 2000
It is proposed that reproductive mode is a critically important but previously overlooked factor in the speciation process and the viviparity-driven conflict hypothesis provides a parsimonious explanation for these patterns in mammalian evolution.
Differential parental nutrient allocation in two congeneric pipefish species (Syngnathidae: Syngnathus spp.)
Results indicate gross classification of brooding structures into one of the three general pouch types does not predict the energetic investment of males in parental care and physiological characterization of the relative investment by each sex to offspring is essential to understanding the functional significance of the brood pouch.