Differences in potential reproductive rates of male and female seahorses related to courtship roles

@article{Masonjones2000DifferencesIP,
  title={Differences in potential reproductive rates of male and female seahorses related to courtship roles},
  author={Heather D Masonjones and Sara M. Lewis},
  journal={Animal Behaviour},
  year={2000},
  volume={59},
  pages={11-20}
}
Dwarf seahorses, Hippocampus zosterae (Syngnathidae), are distinguished by extreme morphological specialization for paternal care, the formation of monogamous pair bonds and mating repeatedly over the course of a breeding season. To determine the potential reproductive rates of male and female dwarf seahorses, we measured (1) the maximum number of offspring produced per breeding cycle when sexually receptive mates were unlimited, and (2) the relative time each sex was unavailable for mating… 

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References

SHOWING 1-10 OF 51 REFERENCES
Male potential reproductive rate influences mate choice in a bushcricket
TLDR
The potential reproductive rate of males had a great impact on their choosiness, whereas variance in female age had no effect, which support recent theoretical models that predict costs, rather than benefits, will primarily influence the level of mate choice.
Decoupling of reproductive rates and parental expenditure in a polyandrous butterfly
TLDR
It is shown that the relative degree of parental expenditure in of&pring is largely decoupled from the degree of mating competition in P. napi, where the male reproductive rate is 8-13 times higher than that of females.
Reproductive costs in two sex-role reversed pipefish species (Syngnathidae)
TLDR
In two species of pipefish the reproductive costs of the two sexes were compared to see how they might influence patterns of sex-role reversal, and in both species the limiting sex, males, faced higher reproductive costs than females, as would be expected in sex- role reversed animals.
Potential Reproductive Rates and the Operation of Sexual Selection
TLDR
This framework for relating sex differences in mating competition to the operational sex ratio, potential reproductive rates, and parental expenditure differs from Triver's concept of the relation between parental investment and mating competition in three ways.
Operational Sex Ratios in Seahorses
TLDR
A study of a laboratory population of the Sri Lankan seahorse Hippocampus fuscus finds that the operational sex ratio (OSR) among mated seahorses is male-biased, because unmated (empty) males can prepare to mate more quickly and can remain ready to mate for longer than can unmated females.
Courtship Behavior in the Dwarf Seahorse, Hippocampus zosterae
The seahorse genus Hippocampus (Syngnathidae) exhibits extreme morpho- logical specialization for paternal care, with males incubating eggs within a highly vascularized brood pouch. Dwarf seahorses,
Quantification of role reversal in relative parental investment in a bush cricket
TLDR
The measurement of male and female investment in reproduction for a nutrient-provisioning bush cricket is reported and it is demonstrated that reversals in relative parental investment underlie courtship role reversals seen in this species.
Seahorses exhibit conventional sex roles in mating competition, despite male pregnancy
TLDR
The laboratory experiments in this paper demonstrate that, contrary to expectations, seahorses exhibit conventional sex roles: male seahorse compete more intensely than females for access to mates, on both the first and final days of courtship.
Paternal care
Reproductive rates, operational sex ratios and mate choice in St. Peter’s fish
TLDR
The sexual differences in PRR were shown to be the main factor causing variation in the OSR, and the faster male reproductive rate may explain why females are more selective for mates despite varying less in quality.
...
...