Unique multiple paternity in the endangered big‐headed turtle (Platysternon megacephalum) in an ex situ population in South China

Abstract

Understanding the mating system and reproductive strategies of an endangered species is critical to the success of captive breeding. The big‐headed turtle (Platysternon megacephalum) is one of the most threatened turtle species in the world. Captive breeding and reintroduction are necessary to re‐establish wild populations of P. megacephalum in some of its historical ranges in China, where the original populations have been extirpated. However, the captive breeding of P. megacephalum is very difficult and this may be due to its mysterious reproductive strategies and special behavior (e.g., aggressive temperament and territoriality). In this study, we achieved successful captive breeding of P. megacephalum by creating a habitat that mimics natural conditions and then investigated its mating system using microsatellite makers. A total of 16 clutches containing 79 eggs of P. megacephalum were collected, and 52 were hatched successfully over two breeding seasons. Of the 15 effective clutches, 6 clutches (40%) exhibited multiple paternity. There was no significant correlation between clutch size and multiple paternity, and no significant difference in hatching success between multiple‐sired and single‐sired clutches. However, there was significant correlation between male body size and the number of offspring, with higher‐ranked males contributing to more clutches. Our results provide the first evidence of multiple paternity and male hierarchy in P. megacephalum. These findings suggest that multiple paternity and male hierarchy should be considered in captive breeding programs for P. megacephalum, and creating a habitat that mimics natural conditions is an effctive way to achieve successful captive breeding and investigate the mating systems of this species.

Home‐site fidelity and homing behavior of the big‐headed turtle Platysternon megacephalum

“…Therefore, it is assumed that the observed behaviors in the present study were not caused by the unsuitability of the microhabitats of the translocation sites. In contrast, the territoriality of bigheaded turtles (Gong et al, 2019) may explain their high home-site fidelity and homing rates.…”

Genetic Diversity of the Critically Endangered Big-Headed Turtle (Platysternon megacephalum) Based on Wild and Traded Samples: Implications for Conservation

“…Keeping turtles in rescue centers in the long term incurs expense and considerable effort. Furthermore, the aggressive behavior of P. megacephalum makes it difficult to keep them for a long time, and the cost of maintaining them in captivity is relatively high because they need to be maintained in individual enclosures [66,67]. Finally, big-headed turtles require clean water and seasonality [66] if they are to thrive and breed, which makes catering for large numbers of them in rescue centers problematic.…”

“…Although genetic screening has been demonstrated to be a useful tool in assisting the appropriate release to the wild of vertebrates that lack provenance information and this approach has been strongly recommended by IUCN [7,12,66], it has rarely been used in practice. One of the barriers is the cost of screening and the number of turtles being seized, especially if more detailed genetic information based on nuclear markers, e.g., microsatellites or single nucleotide polymorphism, is needed to identify genetically distinct populations [39,[68][69][70]. Unfortunately, as most seizures to date have occurred in developing countries and involved their native species, the access to funding sources is restricted or not timely enough to facilitate proper release, which is necessary if the considerable expense of managing a large number of individuals is to be avoided.…”

Genomic analyses reveal three phylogenetic species and their evolutionary histories in the big-headed turtle

“…Currently, the captive breeding of the big-headed turtle has been successful in some turtle farms and reintroduction is a promising measure for the recovery of wild populations. 11 However, big-headed turtles on farms are generally collected from markets and their geographical sources are often unknown. As a result, releasing non-native or hybrid individuals into the wild may increase the risk of extinction of local populations, as is the case for the critically endangered Chinese giant salamander ( Andrias davidianus ).…”