• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.45-56
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• 2021

A male, presumed to be an intergeneric hybrid between Tanakia lanceolata and Rhodeus pseudosericeus, was collected in the Boryeong Daecheoncheon Stream flowing into the Yellow Sea in the Republic of Korea. Morphological and molecular phylogenetic analyses were performed to discriminate the definite origin of the estimated natural hybrid. As a result of the morphological analysis, the color of the dorsal and anal fin rays edges of the natural hybrid individual, the upper and lower body colors followed the morphological characteristics of T. lanceolata, and that blue longitudinal stripe in the center of the caudal peduncle, the incomplete lateral line, and the barbels absent followed the morphological characteristics of R. pseudosericeus. In addition, as a result of the cytochrome b (cytb) gene analysis of mitochondrial DNA (mtDNA), the natural hybrid showed a nucleotide sequence similarity of 99.82 to 100% with T. lanceolata, and the maternal species was identified as T. lanceolata. As a result of the recombination activating gene 1 (rag1) gene analysis of nuclear DNA (nDNA), the natural hybrid showed double peaks pattern reflecting both the single nucleotide polymorphism sites (38 bp) between T. lanceolata and R. pseudosericeus, and the paternal species was identified as R. pseudosericeus. Therefore, a natural hybrid estimated male of Acheilognathinae analyzed in this study was found to be an intergeneric hybrid between a female T. lanceolata and a male R. pseudosericeus.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.146-159
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• 2020

The objective of our study was to analyze the distribution and composition of fish species and their community characteristics in agricultural waterways in the six water systems-Mankyung River, Seomjin River, Namhae Region, Tamjin River, Yeongsan River, and Dongjin River-during 2017-2018. Little is known about the distributions and community characteristics of the aquatic biota of agricultural waterways in Korea, even if the water bodies have important roles as spawning areas or habitats for fish. In this study, we identified 3,633 fish individuals in the waterways, belonging to 53 species, eleven families, and six orders (dominant species: Tanakia koreensis, T. lanceolate) and 7,108 fish individuals in the main rivers, belonging to 57 species, fifteen families, and nine orders. Moreover, three endangered wildlife (designated by the Ministry of Environment, Korea)-T. somjinensis, Acheilognathus majusculus and Coreoperca kawamebari-were found in the waterways. By fish guild analysis, we found that many waterways had a lower proportion of sensitive species and a higher proportion of omnivore species than those of the main rivers, which indicates a feature of a disturbed environment. In addition, by grouping with environmental variables, we found the group of waterways with high substrate complexity had a higher diversity index (Shannon index) and a lower dominance index (Simpson index) than that of simple substrate complexity. Overall, our study represents the characteristics of fish habitats in agricultural waterways and suggests the need to manage them and study further.