The breeding biology of lemon sharks at a tropical nursery lagoon

Abstract

Surprisingly little is known about the reproductive behaviour and breeding biology of most shark species, especially in natural populations. Here, we characterize reproductive patterns and use of a natal nursery at Bimini, Bahamas by lemon sharks, Negaprion brevirostris. We systematically and exhaustively sampled young lemon sharks at Bimini annually from 1995 to 2000 and opportunistically sampled adults over the same period. Out of the 897 young sharks sampled, 119 could be assigned to ve sampled mothers using microsatellite genotyping. Reproductive females showed strong philopatry to the nursery, returning to Bimini every two years to give birth. Each of these females may rely entirely on the Bimini nursery for recruitment. The protection of known nursery grounds should therefore gure prominently in conservation efforts for large coastal shark species. The reconstruction of paternal genotypes indicates that litters are sired by multiple males, and females mate with different males nearly every breeding cycle. The ubiquitous polyandry reported here raises the possibility that genetic incompatibility and post-copulatory paternitybiasing mechanisms may operate in viviparous sharks.

Population dynamics of the reef manta ray Manta alfredi in eastern Australia

“…It may also suggest size-based segregation in M. alfredi populations, with different habitats used by neonates and young-of-year. Many other elasmobranch species give birth in nursery areas where food resources are plentiful and neonate survival is thought to be enhanced due to lower predation pressure (Feldheim et al 2002;Heupel et al 2007;Bansemer and Bennett 2011), but it is unknown whether this is the case in manta rays.…”

Sea turtle nesting distributions and oceanographic constraints on hatchling migration

“…Within these regions, there is often considerable spatial variation in the abundance of individuals (e.g. Page et al 1991;Boyd 1993;Feldheim et al 2002). The spatial variation is typically correlated with ecological resources and environmental conditions favouring the survival of offspring, including the presence of food, shelter and a relative lack of predation (Boyd 1993;Martin 1993;Olivier & Wotherspoon 2005).…”

Relatedness and polyandry of sixgill sharks, Hexanchus griseus, in an urban estuary

“…At least six males contributed to her offspring, but these contributions were skewed because only a few of the males contributed the majority of the genotypes. This is not surprising, as there has been evidence of multiple paternity using similar genetic methods found in every shark species examined thus far (lemon sharks, Feldheim et al 2002;sandbar sharks, Portnoy et al 2007; and Pacific spiny dogfish, Squalus suckleyi (S. Larson unpublished data). Most studies on Carcharhinusplumbeus 0.23-0.53 Not reported Heist and Gold (1999) multiple paternity in sharks have also documented skewed reproductive success with one or two males siring the majority of the offspring (Chapman et al 2004;Portnoy et al 2007).…”

“…One hypothesis explaining higher genetic diversity in sharks is the mating system found in many species. Polyandry (females mating with more than one male), polygyny (males mating with more than one female), and multiple paternity within a litter is recognized in many shark species (Feldheim et al 2002;Portnoy et al 2007;DiBattista et al 2008;Daly-Engel et al 2007. Multiple paternity obviously results in increased diversity within a litter but, due to variance in reproductive success among males noted in many shark species, increased diversity is not likely seen at the population level (Karl 2008;Daly-Engel et al 2010).…”