Genetic Relationship Between Founders of a Threatened Freshwater Turtle in a Mexican Wildlife Management Unit. A Conservation Strategy

Abstract

Management Units for Wildlife Conservation (UMAs according to its Spanish acronym), are used for the ex-situ reproduction of freshwater turtles. These areas, often administered by local communities, are dedicated to conservation and sustainable management. The critically endangered freshwater turtle Dermatemys mawii has been successfully reproduced in several UMAs; however, no genetic management plan has been developed to maintain offspring genetic variability. Therefore, this study aims to determine the kinship relationship and homozygosity through the loci index of founder individuals in three UMAs devoted to the reproduction of D. mawii for the establishment of breeding groups. We collected skin samples of D. mawii in 2017 from 117 founder individuals from three UMAs located in the state of Tabasco, southeast Mexico. Ten specific D. mawii microsatellite markers were used for genotyping the founder individuals. We estimated the pedigree relationship between founders and proposed the formation of three breeding groups to optimize the use of related and non-related individuals to meet UMA-specific objectives and evaluated the genetic diversity retention of the breeding groups. The breeding groups were integrated as follows: 1) conservation breeding group consisting of 16 unrelated females and 7 unrelated males that presented a lower level of homozygosity (< 0.4); 2) research breeding group consisting of 45 females and 16 males that were unrelated or presented a half-sibling relationship and with a medium level of homozygosity (<0.6); and 3) a sustainable breeding group comprising 29 females and 4 males that were not necessarily unrelated and with a high level of homozygosity (> 0.6). Genetic diversity retention (Ho, He) was highest for the conservation breeder group and research breeder group. UMAs can create 3 breeding groups with different objectives: 1) species conservation, 2) research, and 3) sustainable use of species. All breeding groups can retain genetic diversity. Our proposal can enrich conservation actions and sustainable use for D. mawii at both national and international levels, specifically within the Mesoamerican corridor.