• 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 Ichthyology
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• v.21 no.sup1
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• pp.73-73
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• 2009

The modern cartilaginous fishes, class Chondrichthyes, are small group of Pisces, and comprisingmore 1,000 described valid species, and including approximately 190 genera, 55 families, and 15 orders. The Chondrichthyes consists of two subclasses, the Holocephali (chimeras) and the Elasmobranchii(sharks and rays). The dominant subclass Elasmobranchii includes sharks (Selachii) and rays (Batoidea), the former is more diverse than the latter in higher taxa (order, family, genus) but has fewer species. The Batoidea, batoids or rays, has long been recognized as monophyletic, however, the interrelationships of the groups are problematic and uncertain. In order to review biodiversity and systematics of batoids, valid species name and supraspecific taxa from the published materials are studied. Batoids (including sawfishes, Pristiformes; electric rays, Torpediniformes; stingrays, Myliobatiformes; skates, Rajiformes; wedgefishes, Rhiniformes; and guitarfishes, Rhinobatiformes) is speciose and worldwide with about 580 species in 4 to 6 orders, 17 to 19 families, and about 75 genera. In East Asian waters, the previous records of the Batoidea reveal about 170 species belonging to 41 genera, 18 families, 6 orders. The largest group of batoid fauna in the area is order Myliobatiformes comprising about 80 species, 16 genera of 7 families. The predominant families are Dasyatidae (whiptail stingrays: 46 spp. of 6 genera), Arhynchobatidae (softnose skates: 26 spp. of 3 genera), and Rajidae (skates: 21 spp. of 6 genera). The predominant genera are Bathyraja (softnoseskates: 20 spp.), Himantura (whiprays:19spp.), and Dasyatis (fantailstingrays: 18 spp.). There are 23 species in the Yellow Sea, 70 species in the East China Sea, 82 species in the South China Sea, and 58 species in the North Pacific coast of Japan. Batoid fauna from the East Sea (Sea of Japan) is the poorest of the five regions, consisting of 14 species. Korean waters include only 28 species, 16 genera, 10 families and 5 orders of batoids. Two species is torpediniforms, 4 rhinobatiforms, arhynchobatiforms, 11 rajiforms and 10 myliobatiforms. By the earlier works, the systematics and a check list of the valid species of batoids will be presented.