Identification of genetic diversity of Bufo gargarizans and Pelophylax nigromaculatus in the three islands of Chongming insights into aquaculture resources protection

Creatures grown on the island are more susceptible to genetic vulnerabilities because of their isolated nature and often limited genetic diversity. Understanding the genetic structure of these populations is crucial for effective conservation strategies, especially for the species that are commonly found in aquaculture and may inhabit islands. Bufo gargarizans and Pelophylax nigromaculatus were distributed in the Chongming Islands of Shanghai, China. We analyzed mitochondrial DNA cytochrome b (cytb) and D-loop sequences of the populations of the two species across three Chongming islands to investigate genetic diversity, phylogenetics, and infer historical demography, which indicated a lower genetic diversity in island populations compared with their mainland counterparts, reflecting a heightened vulnerability to environmental perturbations and potential extinction risks. Noticeably, a more interlaced genetic pattern was determined in P. nigromaculatus than in B. gargarizans, which was probably attributed to the differences in species' dispersal capabilities among the populations of islands and the mainland. Hence, the genetic analyses propose targeted recommendations for in situ conservation and aquaculture management.