Data from: Facultative parthenogenesis in a critically endangered wild vertebrate

Facultative parthenogenesis — the ability of sexually reproducing species
to sometimes produce offspring asexually — is known from a wide range of
ordinarily sexually reproducing vertebrates in captivity, including some
birds, reptiles and sharks 1, 2 and 3. Despite this, free-living
parthenogens have never been observed in any of these taxa in the wild,
although two free-living snakes were recently discovered each gestating a
single parthenogen — one copperhead (Agkistrodon contortrix) and one
cottonmouth (Agkistrodon piscivorus). Vertebrate parthenogens are
characterized as being of the homogametic sex (e.g., females in sharks,
males in birds) and by having elevated homozygosity compared to their
mother 1, 2 and 3, which may reduce their viability. Although it is
unknown if either of the parthenogenetic snakes would have been carried to
term or survived in the wild, facultative parthenogenesis might have
adaptive significance. If this is true, it is reasonable to hypothesize
that parthenogenesis would be found most often at low population density,
when females risk reproductive failure because finding mates is difficult.
Here, we document the first examples of viable parthenogens living in a
normally sexually reproducing wild vertebrate, the smalltooth sawfish
(Pristis pectinata). We also provide a simple approach to screen any
microsatellite DNA database for parthenogens, which will enable
hypothesis-driven research on the significance of vertebrate
parthenogenesis in the wild.