Abstract
The silky shark (Carcharhinus falciformis) is a pelagic carcharhiniform shark species distributed globally in tropical and subtropical oceans. In this study, we report a seasonal sex segregated aggregation off the southern tip of the Baja California Peninsula and record the distribution and frequency of mating wounds, to determine if males targeted specific regions of the body before and during mating. A total of 210 individual female silky sharks were photographed during mating events from June to July 2021, 63 of which (30%) showed evidence of fresh mating wounds. To quantify differential occurrence of mating wounds in different regions of the body of sampled individuals, we defined 6 regions on each side of the body, and we observed a significant difference in the abundance of mating wounds between these regions (p = < 0.0001). Mating wound frequency did not differ significantly between June and July (p = 0.11), suggesting that these mating events may be longer than previously thought, or that phenological changes could be occurring within populations of C. falciformis in this region. This study highlights the occurrence of a sex segregated aggregation of silky sharks and the implications on their reproductive biology off the tip of the Baja California Peninsula.
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Data availability
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
Change history
20 July 2022
A Correction to this paper has been published: https://doi.org/10.1007/s10641-022-01304-x
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Acknowledgements
The authors would like to thank the local artisanal fishermen communities around the sample area for the information on seasonal sightings of silky sharks in this region. Also, to the crew and safety divers from the Baja Shark Experience team especially Evan Baudin and Gabriel Velázquez for providing in-water logistical support to make this study possible, and to all the volunteers who assisted in the field monitoring trips. F.G.M would also like to thank the Instituto Politécnico Nacional for fellowships (EDI, COFAA).
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D.A.W, J.H.G designing the study. D.A.W, J.H.G, N.M.S collection of data and for assisting in coordinated the field work activities. D.A.W and J.H.G performed analyses and interpretation of the data. D.A.W and J.H.G prepared the manuscript and J.T.K, F.G.M and E.M.H reviewed and contributed to the final version of the manuscript.
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The original online version of this article was revised: The title was incorrectly given as ‘Headline: frequency and distribution of mating wounds in a silky shark aggregation first description of a sex segregated aggregation of silky sharks (Carcharhinus falciformis) and the frequency and distribution of mating wounds off the tip of the Baja California Peninsula’ but should have been ‘First description of a sex segregated aggregation of silky sharks (Carcharhinus falciformis) and the frequency and distribution of mating wounds off the tip of the Baja California Peninsula’.
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Whitehead, D.A., Gayford, J.H., Hoyos, E.M. et al. First description of a sex segregated aggregation of silky sharks (Carcharhinus falciformis) and the frequency and distribution of mating wounds off the tip of the Baja California Peninsula. Environ Biol Fish 105, 953–960 (2022). https://doi.org/10.1007/s10641-022-01297-7
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DOI: https://doi.org/10.1007/s10641-022-01297-7