First evidence of multiple paternity in the bull shark (Carcharhinus leucas)

Abstract

International audienceThe present study assessed the occurrence of multiple paternity in four litters of bull shark Carcharhinus leucas (n¼5, 8, 9 and 11 embryos) sampled at Reunion Island in the Western Indian Ocean. Using 21 microsatellite loci, we revealed that two litters were generated from two sires each, demonstrating for the first time multiple paternity for this species. We also reported a high paternal skew (10 : 1 in Litter 1 and 7 : 1 in Litter 3), which may be because of postcopulatory or post-zygotic selection processes. These results contribute to a better understanding of the reproductive behaviour of the bull shark, which remains poorly documented. The present study must be expanded to assess the frequency of multiple paternity in this species, and to test for genetic or cryptic benefits (convenience polyandry), which is important for long-term conservation and management plans

Reproductive biology, multiple paternity and polyandry of the bull shark Carcharhinus leucas

“…Four litters studied previously (Pirog, Jaquemet, et al ., ) were added to the present study in order to identify males that may have sired several litters, resulting in a total of 16 studied litters.…”

“…Among the four litters already studied with the same loci (Pirog, Jaquemet, et al ., ; litters 1–4, Table ), two of them exhibited evidence of multiple paternity. Among the 12 added litters (litters 5–16, Table ), more than two paternal alleles for at least two loci were observed for seven litters.…”

“…Genotyping was performed using the 21 loci previously used in Pirog, Jaquemet, et al . () and laboratory procedures were conducted as described in Pirog, Blaison, et al . ().…”

“…This species reproduces by placental viviparity, providing nutrients during most of the gestation through a yolk‐sac placenta, a direct connection between mother and embryos (Compagno, ; Parsons et al ., ). Litter sizes range from 1 (Jenson, ) to 14 (Nevill et al ., ) embryos, with typical litter size being 6–8 embryos (Compagno, ; Fowler et al ., ; Jenson, ; Pirog, Jaquemet, et al ., ) with sizes (total length L T ) at birth ranging 50–80 cm (Branstetter & Stiles, ; Cliff & Dudley, ; Compagno, ; Jenson, ; Snelson et al ., ). Total length at sexual maturity varies between localities and sex.…”

First Reconstruction of Kinship in a Scalloped Hammerhead Shark Aggregation Reveals the Mating Patterns and Breeding Sex Ratio

“…The siblingship reconstruction achieved using COLONY2 and confirmed with SNP PEDIGREE allowed us to identify many examples where putative fathers and putative mothers appeared to have progeny with multiple partners. Polyandry in Elasmobranchs has been documented in the majority of species studied to date using litters collected from the uteri of pregnant females captured on fishing boats (e.g., Daly-Engel et al, 2006;Boomer et al, 2013;Pirog et al, 2016;Rossouw et al, 2016;Green et al, 2017). However, the results of this study demonstrate polygyny in hammerhead sharks for the first time.…”