Data from: Facultative parthenogenesis in a critically endangered wild vertebrate
Fields, Andrew T.; Feldheim, Kevin A.; Poulakis, Gregg R.; Chapman, Demian D. (2016), Data from: Facultative parthenogenesis in a critically endangered wild vertebrate, Dryad, Dataset, https://doi.org/10.5061/dryad.6mt23
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.
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