• Title/Summary/Keyword: Rajiformes

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Synopsis of the Family Dasyatidae (Elasmobranchii, Rajiformes) from Korea

  • LEE Chung Lyul;JOO Dong Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.6
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    • pp.745-753
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    • 1996
  • Taxonomic revision of the family Dasyatidae was studied on the basis of the specimens collected from the Korean coasts from June 1994 to January 1996. The family Dasyatidae of Korea was classified into 6 species in genus Dasyatis, and the key to species was proposed with their synonyms and distributions. Three new records from Korea were described and figured in detail: Dasyatis acutirostra Nishida and Nakaya, D. matsubarai Miyosi and D. sinensis (Steindachner). Most species of the Korean stingrays are shared with those of China and Japan.

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First Record of an Abnormal Bathyraja brachyurops (Rajiformes: Arhynchobatidae) Collected from the Southwest Atlantic Ocean (남서대서양에서 채집된 Bathyraja brachyurops (Rajiformes: Arhynchobatidae) 기형의 첫 보고)

  • Min-Gyoon Park;Eunjung Kim;Jin-Koo Kim
    • 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.

Egg Capsule of Hongeo koreana (Chondrichthyes: Rajiformes: Rajidae) (고려홍어 Hongeo koreana의 난각(연골어강: 홍어목: 홍어과))

  • Jeong, Choong-Hoon;Kim, Jin-Koo
    • Korean Journal of Ichthyology
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    • v.21 no.4
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    • pp.283-286
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    • 2009
  • The egg capsule of Hongeo koreana is newly described based on two egg capsules extracted from the uterus of a female collected near the type locality, the southwestern coast of the Korean Peninsula. The egg capsule of H. koreana has the following characters: medium sized, measuring 124.5~133.7 mm in total length including horns, 102.8~109.4 mm in length excluding horns, and 41.0~42.2 mm in maximum width; asymmetrical, with the egg capsule more convex ventrally in lateral view; the surface relatively smooth, with longitudinal striations distinct, and covered with masses of sticky silky fibers; anterior and posterior aprons distinct; all four horns short, tube-like in shape, elliptical in cross section, anterior horns recurved inwardly; respiratory fissure present at tip of each of the four horns. The color of the fresh capsule is bright brown.

A Review of Taxonomic Studies of Batoids (Chondrichthyes: Batoidea) from East Asian Waters (동아시아 수역의 가오리상목의 분류학적 검토)

  • Jeong, Choong-Hoon
    • 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.

Variations of Fish Community and Fish Density on Artificial Reefs (인공어초어장의 어류 군집상과 어획량 변동)

  • LEE Jeong-Woo;KANG Young-Shil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.5
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    • pp.535-548
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    • 1994
  • Community structures and fish densit were investigated on three different types of artificial reefs, dice, turtle artificial reef and tubes, constructed in the Korean waters. Variations of fish fauna according to type of artificial reef and the proper artificial reef in each area for optimizing harvest were discussed. Fish were captured by trammel gill net during May, June, September and November, 1988 and both identified and counted. Fourty-five fish species were found in the artificial reefs. Of these, Sebastes spp., Hexagrammos otakii, Pleuronectidae, Navodon modestus and Stephanolepis cirrhifer showed high occurrence-frequency. The dominant species groups were coastal settlement, demersal or rock fishes such as Pleuronectidae, Rajiformes, Stephanolepis cirrhifer, Navodon modestus, Hexagrammos otakii and Sebastes spp. in all of the Artificial reefs except the oceanic area of southern waters. Scomber japonicus was predominant in the oceanic area of southern waters. Composition of demersal, rock and pelagic fishes were different depending on the types of artificial reef. Dice artificial reefs were occupied by rock fish, on the other hand turtle artificial reefs were dominated by dermersal fish. Fish density was high at the dice artificial reef in all survey areas except the middle area of Eastern waters, with high fish density evident in the Tube artificial reef. Fish community structures were remarkably different between Dice and Turtle artificial reefs. The Tube artificial reef showed intermediate characteristics between the above two types of artificial reefs. The coastal areas of Southern waters and the middle and southern areas of Western waters revealed similar fish fauna. Results from the oceanic areas of Southern waters were well associated with the middle and southern areas of Eastern waters.

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