Kareius bicoloratus is a commercially important flatfish in Korean coastal fisheries and an ecologically relevant benthic species in nearshore ecosystems. To evaluate how multiple biological and environmental factors jointly shape flatfish morphology, we analysed 81 morphometric indices and two‐dimensional geometric morphometrics (GMM) in wild K. bicoloratus collected from two Korean coastal regions, incorporating size, sex an...

The black shinner Pseudopungtungia nigra is an endangered freshwater fish endemic to Korea, and standardized anesthetic protocols are needed for conservation-related hatchery handling. This study evaluated the effects of water temperature and MS-222 concentration on anesthetic induction and recovery responses in hatchery-reared juvenile P. nigra of approximately 3 cm total length. Juveniles were exposed to four MS-222 concentr...

The endangered freshwater fish Gobiobotia brevibarba is endemic to Korea and threatened by habitat disturbance in major river systems. We investigated four wild populations from the Han River basin (IJR, BHR, NHR) and the Geum River basin (GR) using eleven microsatellite loci to assess genetic diversity, population structure, and contemporary gene flow. All populations showed relatively high genetic diversity (HO = 0.709–0.800...

Artificial crossbreeding is a critical strategy in the restoration of endangered freshwater fishes with small, fragmented populations, where natural spawning alone cannot reverse genetic erosion. This study examined the genetic diversity and fitness traits of crosses between genetically distant (HGD) and closely related (LGD) broodstock individuals of Pseudopungtungia nigra, an endangered Korean freshwater fish. Using ten micr...

Background Freshwater endemism is thought to have been formed through the vicariance of connected water systems or the process by which ancestral populations colonized specific areas. The Korean Peninsula is well recognized for its high level of freshwater endemism with about 40% of freshwater fish species being endemic. Objective In this study, we attempted to reconstruct the process of speciation and phylogenetic dispersal o...