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Simple Summary: The global economic cost of managing invasive species exceeded $423 billion annually in 2019 and has increased at least fourfold every decade since 1970. In South Korea, the annual damage caused by invasive species is estimated to be between $93 million and $51.68 million. South Korea is vulnerable to invasive species and the cost of invasive species is estimated to be the highest among other countries, indicating the need for policy measures and responses. Most of the invasive reptiles in South Korea are introduced and released by humans. The hybridization of the Chinese striped-necked turtle Mauremys sinensis and Reeves' turtle M. reevesii identified in the current study is also suspected to have been introduced from captivity into the wild, raising alarm bells. This suggests that the introduction of hybrids into the wild could pose a serious problem for biodiversity, especially for the M. reevesii, as it could undermine the genetic diversity of the population. Public awareness and education are needed to preserve South Korea's biodiversity, and efforts must be made to reduce the number of exotic reptiles introduced into the wild. The Chinese striped-necked turtle Mauremys sinensis, introduced into South Korea presumably in 2012, is considered an invasive alien species owing to its devastating impact, including hybridization with the native protected species Reeves' turtle M. reevesii. Recently, the presence of M. sinensis has been confirmed throughout the country, and several sympatric areas with M. reevesii have been reported. Thus, field surveys were conducted at 47 sites across M. sinensis and M. reevesii habitats in South Korea to determine the extent of hybridization. Five sympatric sites were confirmed, and hybrid individuals were identified at four sites. Genetic analyses (COI and R35) of two individuals from Jeju Island confirmed maternal M. reevesii and paternal M. sinensis lineages. Hybridization presumably does not occur under natural conditions, and the hybrids likely originated from captive breeding. This study identifies for the first time the habitats of M. sinensis and its hybrids in the wild of South Korea. The management measures proposed in the current study could be of value for the conservation of the native species; however, our study did not include reproductive monitoring, and there is a need for such surveys as well as for systematic management of non-native turtles introduced into South Korea. [ABSTRACT FROM AUTHOR]

The introduction of exotic species and the associated impacts are increasing worldwide due to the development and increase in transportation and international trade. As new populations of the non-native Gekko japonicus and G. swinhonis have recently been discovered in South Korea, this study was conducted to investigate the distribution of these species, evaluate the establishment potential of non-native populations and infer their routes of introduction. The study comprised targeted field surveys around the major international ports, generation of ecological niche models (ENMs), based on the known distributions and comparison of the ecological niches of the two species. The results suggest that G. japonicus and G. swinhonis are primarily distributed in the humid subtropical climate (Cfa) and the monsoon-influenced hot-summer humid continental climate (Dwa), respectively. According to the ENMs predicted across South Korea, suitable habitats for G. japonicus were located along the western and southern coasts of the country, whereas those for G. swinhonis were predicted along the western coastal regions and several major cities inland. These distributional patterns may be attributed to adaptations of the two gecko congeners to distinct climatic conditions leading to divergent ecological niches. Considering the known distributions of the two species in South Korea, the most likely routes of introduction are accidental translocations through international trade and the inland populations most likely originated from human-mediated dispersals along the major rivers. This study highlights the need to implement quarantine procedures for international cargo arriving in South Korea. Additional field surveys are further recommended to focus on urban areas adjacent to international ports and major rivers to curtail further introductions of non-native geckos. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the reutilization, distribution, and import status of invasive alien turtles in South Korea. The results showed that a total of nine invasive alien turtle species including Trachemys scripta, which is designated as an ecosystem disturbing species (EDS), were traded in the traditional market, and 84 of 169 turtles registered through the National Animal Welfare Information System were reintroduced to new breeders. Additionally, the distribution of invasive alien turtles was confirmed at 341 points in 109 cities, and we found that, on average, 7 tons of non-indigenous turtles are imported annually from over 20 countries to South Korea. These results indicate the urgent need for efficient management of invasive turtles in South Korea. Therefore, we suggest (1) activating a purchase program of EDS through local governments, (2) establishing links with research institutions and experts to improve the initial species identification accuracy of the National Animal Welfare Information System, (3) establishing a follow-up management system after the designation of EDS, and (4) providing a free collection service for exotic turtles abandoned by breeders. Finally, this study provided the current distribution of invasive alien turtles in South Korea and the exotic turtle import status over 21 years. [ABSTRACT FROM AUTHOR]

In this study, we use a specimen from wild-caught individual to determine the complete mitochondrial genome of the Amur soft-shelled turtle (Pelodiscus maackii). The complete mitogenome of P. maackii has 16,258 bp in length and consists of 13 protein-coding genes (PCGs), 22 tRNAs, two rRNAs, and one control region. The arrangement of genes of P. maackii is identical with previously reported mitogenomes in the family Trionychoidea. According to our result, the ML tree for the phylogenetic reconstruction revealed that the individuals used in present study is closely related with the previously reported sequences of P. sinensis (AY962573 and MG431983) in p-distance 0.7% and 2.5%. [ABSTRACT FROM AUTHOR]

Population declines and extinctions of amphibians have been attributed to the chytrid fungus Batrachochytrium dendrobatidis ( Bd), especially one globally emerging recombinant lineage (' Bd- GPL'). We used PCR assays that target the ribosomal internal transcribed spacer region ( ITS) of Bd to determine the prevalence and genetic diversity of Bd in South Korea, where Bd is widely distributed but is not known to cause morbidity or mortality in wild populations. We isolated Korean Bd strains from native amphibians with low infection loads and compared them to known worldwide Bd strains using 19 polymorphic SNP and microsatellite loci. Bd prevalence ranged between 12.5 and 48.0%, in 11 of 17 native Korean species, and 24.7% in the introduced bullfrog Lithobates catesbeianus. Based on ITS sequence variation, 47 of the 50 identified Korean haplotypes formed a group closely associated with a native Brazilian Bd lineage, separated from the Bd- GPL lineage. However, multilocus genotyping of three Korean Bd isolates revealed strong divergence from both Bd- GPL and the native Brazilian Bd lineages. Thus, the ITS region resolves genotypes that diverge from Bd- GPL but otherwise generates ambiguous phylogenies. Our results point to the presence of highly diversified endemic strains of Bd across Asian amphibian species. The rarity of Bd- GPL-associated haplotypes suggests that either this lineage was introduced into Korea only recently or Bd- GPL has been outcompeted by native Bd strains. Our results highlight the need to consider possible complex interactions among native Bd lineages, Bd- GPL and their associated amphibian hosts when assessing the spread and impact of Bd- GPL on worldwide amphibian populations. [ABSTRACT FROM AUTHOR]

We studied and compared the age structure, body size, and growth rates of field populations of two Korean salamander species (Hynobius yangi and Hynobius quelpaertensis) to elucidate important aspects of basic population dynamics of these two endemic Hynobius species. In both populations, females were sexually mature at three years of age, while H. yangi and H. quelpaertensis males matured at two and three years of age, respectively. Both males and females of H. yangi and H. quelpaertensis attained a maximum age of 11 years and 10 years, respectively[0]. In both species, the snout-vent length (SVL) and body weight (BW) of the females were greater than those of the males. The SVL, BW, and asymptotic SVL of both male and female H. yangi were smaller than those of H. quelpaertensis. The adult growth rates after sexual maturation of male and female H. yangi were lower than those of H. quelpaertensis, possibly resulting in the smaller body size of the former, although overall growth coefficients were not significantly different between the two species. We also compared the age structure and growth rates of three Korean and three Japanese species of Hynobius. [ABSTRACT FROM AUTHOR]