title: Isolation and genetic diversity of endangered grey nurse shark (Carcharias taurus) populations.
abstract: Anthropogenic impacts are believed to be the primary threats to the eastern Australian population of grey nurse sharks (Carcharias taurus), which is listed as critically endangered, and the most threatened population globally. Analyses of 235 polymorphic amplified fragment length polymorphisms (AFLP) loci and 700 base pairs of mitochondrial DNA control region provide the first account of genetic variation and geographical partitioning (east and west coasts of Australia, South Africa) in C. taurus. Assignment tests, analysis of relatedness and Fst values all indicate that the Australian populations are isolated from South Africa, with negligible migration between the east and west Australian coasts. There are significant differences in levels of genetic variation among regions. Australian C. taurus, particularly the eastern population, has significantly less AFLP variation than the other sampling localities. Further, the eastern Australian sharks possess only a single mitochondrial haplotype, also suggesting a small number of founding individuals. Therefore, historical, rather than anthropogenic processes most likely account for their depauperate genetic variation. These findings have implications for the viability of the eastern Australian population of grey nurse sharks.
authors.affiliation: Macquarie University, Department of Biological Sciences, Sydney, NSW 2109, Australia. astow@bio.mq.edu.au
authors.forename: Adam
authors.initials: A
authors.lastname: Stow
authors.forename: Kyall
authors.initials: K
authors.lastname: Zenger
authors.forename: David
authors.initials: D
authors.lastname: Briscoe
authors.forename: Michael
authors.initials: M
authors.lastname: Gillings
authors.forename: Victor
authors.initials: V
authors.lastname: Peddemors
authors.forename: Nicholas
authors.initials: N
authors.lastname: Otway
authors.forename: Robert
authors.initials: R
authors.lastname: Harcourt
mesh_terms: D025041:Animal Migration; D000818:Animals; D001315:Australia; D004272:DNA, Mitochondrial / Q000032:analysis / Q000235:genetics; D014644:Genetic Variation; D010802:Phylogeny; D011110:Polymorphism, Genetic; D011156:Population Density; D012754:Sharks / Q000145:classification* / Q000235:genetics*; D013019:South Africa
chemical_list: D004272:DNA, Mitochondrial