• Proceedings of the Zoological Society Korea Conference
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• 1998.04a
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• pp.33-33
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• 1998

The most recent, Jeong and Nakabo (1997) described Raja koreana as a new species based on an adult female specimen collected from the southwestern coast of Korean Peninsula. Raja koreana has several unique characters not shared with any other supraspecific taxa of Rajoidei, but it was provisionally included in the genus Raja because of having no information of its clasper. Later, two mature males and a few specimens of the species were collected from near the type locality. Therefore, a new genus should be erected for this species. The new genus is characterized by the followings: Rostral shaft straight, narrow and thick in depth: unsegmented base with filamentous cartilage. Dorsal surface of tail with a row of distinct thorns along midline, patches of distinct thorns anterior to first dorsal fin and between first and second dorsal fins in bathe sexes; most thorns directed anteriorly, and thornlets directed posteriorly. Scapulocoracoid comparatively short and high, rear corner high, without anterior bridge, postventral fenestra expanded. Distal tip of accessory terminal 1 claspser cartilage well separated from the tip of accessory terminal 2 clasper cartilage.

• Korean Journal of Ichthyology
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• v.17 no.4
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• pp.229-235
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• 2005

Sexual maturity of Korean skate, Raja koreana, was investigated based on 89 specimens caught between September 2002 and December 2003 in the southwestern sea of Korea. Clasper development was slow between 35 cm and 52.5 cm TL, increased abruptly between 59.5 cm and 71 cm TL, and thereafter decreased, showing an overall sigmoidal growth pattern. Unlike other skates and sharks, Korean skate males were already histologically mature before the claspers lengthened. Although the egg capsules were found in May and November in Korean skate females, histological findings indicated that spawning occurred throughout the year except summer in females but all the time in males.

• The Korean Journal of Zoology
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• v.3 no.2
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• pp.9-12
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• 1960

Drosophila (Drosophila) trilineata sp.nov. : 국명 세줄등초파리 . 1. 본 종은 1958년 8월 6일에 울릉도의 성인봉에서 그리고 1958년 9월 5일 광릉에서 채집된바, 외형이 Drosophila trivittata Strobl 과 혹사하기에 비종으로 잘못 동정발표하였던 것이다. 연이나 1959년 10월 영국 Edinburgh 대학의 E.B. Basden이 이 본종의 표본을 관찰한 다음 저자가 채집한 상기종은 Strobl 종이 아니고 신종인 듯 생각한다는 암시를 받았기에 그 후세밀히 조사한 바 신종으로 신정할 수있었기에 여기서 발표하는 바이다. 2. 본종은 외형 특히 중배흉부의 stripe의 모양으로 보아 Drosophila trivittata Strobl 과 혹사하나 무미 plate 의 측부에 뚜렷한 knob가 있다는 점, genital arch와 clasper의 기리의 관계, phallic organ 의 형태, egg-guide 의 강모등에 뚜렷한 차이가 있다. 본종은 명백한 fungus feeder 로서 laboratory breeding 은 불가능이었다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.916-922
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• 2023

An abnormal shape of Bathyraja brachyurops was first reported from the catch of a bottom trawl in the southwest Atlantic Ocean in June 2022. Both pectoral fins of the specimen did not fuse with the head, resulting in a horn-like structure separated from the sides of the eyes. Analysis of mitochondrial DNA cytochrome c oxidase subunit I sequences showed that our specimen was perfectly matched to Bathyraja brachyurops registered with the National Center for Biotechnology Information. Our specimen possessed the following morphological features: a pair of flexible but elongated and pointed horns on the head; rough dorsal disc, densely covered with numerous small denticles on the head, anterior margin of pectoral fins and median line of the disc; a thorn between the first and second dorsal fins; and a pair of large ocelli at the base of pectoral fins. Unlike the normal B. brachyurops, our specimen had a slender clasper and no nuchal thorns, which may be related to the morphological abnormality. The horn-like structure on the head may be owing to the lack of fusion between the pectoral fins and head during early embryonic development.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.1
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• pp.30-36
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• 2022

We collected a total of four butterfly ray specimens (Gymnura japonica, 213.4-695.0 mm in total length) in Korea from 2016 to 2021 and investigated their morphological and molecular characteristics in order to clarify their taxonomic status. These features are summarized as follows. Disc lozenge-shaped, 1.8-2.0 times broader than long. Tail very short, post-cloaca length 23.9-28.2% in disc width. Snout short, no rostral cartilage. Clasper short, no hook. Dorsal surface uniform yellow or brownish grey, with or without rounded light yellow spots. An analysis of 434 base-pair sequences of mitochondrial DNA cytochrome c oxidase subunit I showed that all four specimens corresponded to G. japonica from Japan (Kimura-2-parameter distance = 0-0.2%), suggesting that the color patterns found may be due to intraspecific color variation. G. japonica resembles Gymnura poecilura but differs in that it has a shorter tail length to disc width (23.9-28.2% in G. japonica vs. 40.1-48.3% in G. poecilura). This study revealed that G. japonica occurred in areas affected by the Tsushima Warm Current, tentatively suggesting that G. japonica may be an indicator species for monitoring marine ecosystem changes due to climate change.