Parentage Assignment Reveals Multiple Paternity in the Critically-Endangered Guatemalan Beaded Lizard (Heloderma Charlesbogerti)

Within captive management programs for species of conservation concern, understanding the genetic mating system is of fundamental importance, given its role in generating and maintaining genetic diversity and promoting opportunities for sperm competition. If a goal of a conservation program is reintroduction, knowledge of the mating system may also inform prediction models aimed at understanding how genetic diversity may be spatially organized, thus informing decisions regarding where and which individuals should be released in order to maximize genetic diversity in the wild population. Within captive populations, such information may also influence how animals are maintained in order to promote natural behaviors. Here we investigate the genetic mating system of the Guatemalan beaded lizard, Heloderma charlesbogerti, a member of a genus lacking such information. A group of adult male and female H. charlesbogerti were co-habited for five years during the species perceived breeding season. Through genomic parentage analysis, 50% of clutches comprising multiple offspring were found to result from polyandry, with up to three males siring offspring within single clutches. Furthermore, males were found to be polygamous both within and across seasons, and females would exhibit promiscuity across seasons. As such, within this captive environment, where opportunities existed for mating with multiple sexual partners, the genetic mating system was found to be highly promiscuous, with multiple paternity common within clutches. These findings are novel for the family Helodermatidae, and the results have broader implications about how reproductive opportunities should be managed within captive conservation programs.

Very low rate of multiple paternity detected in clutches of a wild agamid lizard

Genetic mating systems described for squamate reptiles range from primarily monogamous to completely polygynandrous. The presence of female multiple mating is almost ubiquitous among squamates and even occurs, albeit at a low rate, in socially monogamous species. Here we examine the genetic mating system of the territorial tawny dragon lizard (Ctenophorus decresii). Paternity was assigned to captive-born hatchlings using eight microsatellite loci, revealing a 4% rate of multiple paternity. One-quarter of males sired more than one clutch, although multiple mating by males is likely underestimated. The rate of multiple paternity in C. decresii represents one of the lowest among squamates and may be a result of successful male territoriality. However, the observed low rate of multiple paternity does not eliminate the possibility of widespread female multiple mating due to the potential for sperm storage and sperm competition. We conclude that the tawny dragon lizard employs a predominantly polygynous genetic mating system.