Optimization and application of a forensic microsatellite panel for two endangered freshwater turtle species (Cuora flavomarginata and Mauremys mutica) in Taiwan

Abstract

Wildlife trafficking of tortoises and freshwater turtles (TFTs) remains a significant global concern, with many species falling victim to illegal trade. Cuora flavomarginata and Mauremys mutica are freshwater turtles native to Taiwan that have fallen victim to illegal poaching and trafficking. The large number of confiscated individuals is increasing the burden on rescue centers. Nevertheless, the inability to determine their origin makes it challenging to conduct field releases. In this study, we will test and characterize of microsatellites for C. flavomarginata and M. mutica in Taiwan for the application in conservation genetic or wildlife forensic studies. Out of the 19 microsatellite primers designed for M. mutica, 15 showed cross-species amplification in C. flavomarginata. The 12 and 11 unlinked microsatellites for C. flavomarginata and M. mutica displayed a marked ability to distinguish between individuals with a high degree of resolution. The cumulative probability of identifying unrelated individuals (cPI) and siblings (cPIsibs) in these microsatellites were 3.94 × 10⁻¹⁴ and 1.66 × 10⁻⁵ for C. flavomarginata, and 3.33 × 10⁻¹³ and 2.91 × 10⁻⁵ for M. mutica. However, it is worth noting that the levels of genetic diversity observed in both species were lower than those in other freshwater turtles. Our results clearly demonstrated that the high-resolution microsatellite panel could be effectively utilized for individual identification. To further enhance our efforts, we plan to collect samples from all existing wild populations in Taiwan to establish a comprehensive reference genotyping database. This database will play a crucial role in pinpointing the geographic sources of confiscated samples in future forensic work.