title: Virgin birth in a hammerhead shark.
abstract: Parthenogenesis has been documented in all major jawed vertebrate lineages except mammals and cartilaginous fishes (class Chondrichthyes: sharks, batoids and chimeras). Reports of captive female sharks giving birth despite being held in the extended absence of males have generally been ascribed to prior matings coupled with long-term sperm storage by the females. Here, we provide the first genetic evidence for chondrichthyan parthenogenesis, involving a hammerhead shark (Sphyrna tiburo). This finding also broadens the known occurrence of a specific type of asexual development (automictic parthenogenesis) among vertebrates, extending recently raised concerns about the potential negative effect of this type of facultative parthenogenesis on the genetic diversity of threatened vertebrate species.
authors.affiliation: Guy Harvey Research Institute, Oceanographic Centre, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, FL 33004, USA.
authors.forename: Demian D
authors.initials: DD
authors.lastname: Chapman
authors.forename: Mahmood S
authors.initials: MS
authors.lastname: Shivji
authors.forename: Ed
authors.initials: E
authors.lastname: Louis
authors.forename: Julie
authors.initials: J
authors.lastname: Sommer
authors.forename: Hugh
authors.initials: H
authors.lastname: Fletcher
authors.forename: Paulo A
authors.initials: PA
authors.lastname: Prodöhl
mesh_terms: D000483:Alleles; D000818:Animals; D005260:Female; D005838:Genotype; D006720:Homozygote; D018895:Microsatellite Repeats; D010312:Parthenogenesis / Q000235:genetics*; D012754:Sharks / Q000502:physiology*