• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.136-142
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• 2020

Morphology and osteology of the slender ribbonfish, Trachipterus ishikawae was described and figured in detail. The morphological characteristics are as follow: body elongate and compressed; upper jaw protrusile; tubercles along ventral edge of body and tail; eyes are large; body naked; caudal fin long and at a right angle to the body; from (3~4)+(7~8) gill rakers; from 180 to 185 dorsal fin rays, from 12 to 13 pectoral fin rays; 9 caudal fin rays and 5+2 short spine at caudal spine. The osteological characteristics are as follow: premaxillary is long and has four teeth; dentary is triangle shape; interopercle and subopercle are wide and flat; 5 branchiostegal rays; post clavicle is thin and long; from 79 to 80 centrum; posterior vertebrae elongate; 5~6 tubercles at urostyle bone.

• Fisheries and Aquatic Sciences
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• v.21 no.12
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• pp.37.1-37.10
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• 2018

The larvae and juveniles of Porocottus leptosomus belonging to the family Cottidae were collected (n = 95, 3.9-16.5 mm in body length, BL) from Busan, Korea, in March 2015. The larvae and juvenile were identified using DNA barcoding as P. leptosomus, and their morphological description was presented in detail. The yolk-sac larvae (3.9-5.6 mm BL) body was slightly compressed, the head was large, the eye was round and large, and the anus was before the middle of the body. The preflexion larvae (5.2-10.0 mm BL) body length drastically increased; caudal fin rays began to occur. The flexion larvae (9.4-11.8 mm BL) notochord flexion started; dorsal, pectoral, and anal fin rays began to occur; pelvic fin buds are seen; they possessed a pair of parietal spine; and a pair of supraocular cirri was first to develop. At 12 mm BL, the notochord was completely flexed. The larva stage (3.9-12.6 mm SL) had the stellate melanophores in the head, isthmus, gut, and tail (along to the ventral midline). During the juvenile stage (11.4-16.5 mm BL), melanophores covered the head and began to form five black bands on the side of the body. The larvae of P. leptosomus spent pelagic life, but moved to the bottom during the juvenile stage. The larvae and juveniles of P. leptosomus differ from other cottid larval fishes by body shape, melanophore head pattern, and spine development. P. leptosomus can be distinguished from Porocottus allisi by morphological development and the occurrence of larval fish: preopercular spine development, melanophore pattern, and caudal fin development.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.106-113
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• 2020

This study identified the differences in the morphometric characteristics of the truss and classical dimensions between diploid and triploid Far Eastern catfish, Silurus asotus, and provided methods for sorting diploid and triploid Far Eastern catfish based on morphometric observations. The significant variables were the direct distance between the anterior edge of the lower lip and the anterior insertion of the dorsal fin(DALAD), the horizontal distance between the anterior edge of the lower lip and the anterior insertion of the ventral fin (HALAV), the direct distance between the anterior edge of the upper lip and the first nostril(DAUF), the direct distance between the anterior edge of the upper lip and the second nostril(DAUS), the interorbital width(IW), and the mandible barbel length (ManBL). The more significant variables were HALAV, DALAD, DAUF, IW, and DAUS. The most useful combination of variables for separating the two groups was DALAD, IW, and DAUF, which correctly classified 85% of the catfish as triploid or diploid, and that percentage was the maximum degree of value possible (p<0.05). Triploid Far Eastern catfish had a high rate of growth in the head region and body depth during the first year after hatching. Triploid Far Eastern catfish had smaller heads and shorter mandible barbels than diploid Far Eastern catfish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.1017-1022
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• 2021

We collected a specimen of Heniochus diphreutes Jordan, 1903 belonging to the family Chaetodontidae on December 26, 2020 in Pohang-si, Gyeongsangbuk-do, using the set net. Although, H. diphreutes is morphologically very similar to Heniochus acuminatus, it can be distinguished from the latter based on the number of dorsal fin spines, mostly 12 in H. diphreutes vs 11 in H. acuminatus, and the percentage of snout length in head length, which is less than 12% in H. diphreutes vs more than 13% in H. acuminatus. Compared to H. acuminatus, H. diphreutes has a shorter snout, two-three rows of teeth, convex ventral profile of the head, more angular anal fins, and a black pattern extending to the longest soft rays on the posterior part of the anal fin. Molecular analyses showed that our specimen perfectly matched H. diphreutes based on mtDNA COI sequences data. We propose a new Korean name for H. diphreutes, "Jjal-beun-ib-du-dong-ga-li-dom".

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.3
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• pp.324-330
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• 2023

We investigated the relative growth and squamation of larvae and juveniles of cultured Larimichthys polyactis. Analysis of the relative growth of larvae and juveniles showed that their preanal length, head length, eye diameter, body depth, and snout length increased with growth. There was no significant chage in the relative growth. The ratio of preanus length to standard length (SL) increased rapidly until SL was approximately 12 mm, and then increased gradually. Cycloid scales first appeared on the lateral line, progressed to the abdominal cavity at 15.13 mm SL, and expanded to the occipital region, base of pectoral fin, and ventral region of the eye at 17.82 mm SL. At 18.03 mm SL, scales formed on the cheek, and those at the base of pectoral fin and in the abdominal cavity were connected to each other. At 19.06 mm SL, major part of the head was covered by scales, except near the lower jaw. Cycloid scales on the lateral line changed to ctenoid scales at the range of 31.71-32.24 mm SL, and those on the nape changed at the range of 69.02-70.84 mm SL. Our results may help to establish conservation and management strategy for Larimichthys polyactis aquaculture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.179-188
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• 1981

The authors made an investigation concerning the geographical distribution and some major differentiations in morphological characteristics associated with the each habitat, of the pond smelt, Hypomesus olidus, which was introduced into Korea more than 50 years ago. Major characteristics utilized for the comparison study were upper jaw (maxillary), number of fin rays, scale structure, vertebral count, number of pyloric caeca, number of gill rakers, and the relative measurements of these and other internal characters. 1. The main areas of natural distribution are Paro Lake, Soyang Lake, Han River, Euirim Lake, and Ogjeong Lake (or Unam Lake) and the tributaries of these waters. 2. Morphological variations varied when the mean values of measurements from each area were compared with the standard measurement value by mosaic comparison, and in some instances a significant variation was found. 3. The most significant variations were found in the number of fin rays of pectoral and anal fins; the lengths from the tip of snout to the origin of pectoral fin, from snout to ventral fin, and from snout to anal fin, relative to standard body length; eye depth relative to head length; upper jaw: the number of pyloric caeca and the scale structure. Variations, on the other hand, by each habitat were not clear in the numbers of ventral and dorsal fin rays, gill rakers, vertebrae and lateral line scale : and the depth of caudal peduncle and distance from the tip of snout to the origin of dorsal fin relative to standard body length. 4. The scales of pond smelt showed some differences in the shape of scales, the shape and position of the focus and the number of ridges according to the scale positions on the body. No radii were present. The relations between longitudinal and transverse diameters of the scale suggest that the pond smelts of Soyang Lake and Un-am Lake are closely related, and those of Han River and Euirim Lake are also closely related. 5. The geographical variations in morphology of the pond smelt seem to have resulted from the variations in turbidity, water temperature, salinity (rather conductivity) and currents. 6. From the results obtained, it may be concluded that such factors as supramaxillary, relation between scale length and its breadth, number of caudal vertebrae and eye depth relative to head length may be used as the key characters for the classification of geographical varieties of Pond smelt.

• Animal Systematics, Evolution and Diversity
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• v.14 no.1
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• pp.43-49
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• 1998

The taxonomic revision of the genus Carcharhinus in Korea was made based on the shark specimens collected in the western and southern coasts including Cheju Isl. of Korea from July 1996 to April 1997. Five species were recognized from the Korean waters and they are described herein. Among them, two species of Carcharhinus dussumieri (Valenciennes, 1839) and Carcharhinus sorrah (Valenciennes, 1839) were collected for the first time from the Cheju Isl. coast of Korea. Carcharhinus dussumieri differs from other species of genus Carcharhinus in following morphological characters: a black or dark spot on the sencond dorsal fin but no other markings, a small first triangular dorsal fin and a second dorsal fin with a short inner margin, and Carcharhinus sorrah: conspicuous black tips on the ventral caudal lobe, pectoral and second dorsal fins, and low second dorsal with a inner margin.

• Korean Journal of Ichthyology
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• v.29 no.4
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• pp.272-276
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• 2017

This is the first report of Cantherhines pardalis (Tetraodontiformes: Monacanthidae) from Korea. A single specimen (105.4 mm in SL) was collected from the coastal waters of Busan by gill net on 20 June, 2012. This species is characterized by having the following morphological traits: II, 34 dorsal fin rays; 31 anal fin rays; 13 pectoral fin rays; caudal peduncle without large spines; spine row on the lateral side of first dorsal spine distinct; posterior end of pelvic with encasing scales distinctly more protruding than ventral flap. This species is similar to C. dumerilii except for the number of spines on caudal peduncle (none in C. pardalis vs. two pairs in C. dumerilii). Based on morphological and molecular approaches, the specimen was identified as C. pardalis. We add C. pardalis to Korean fish fauna and propose the new Korean names "Yuk-gak-mu-nui-jwi-chi" for the species.

• Korean Journal of Ichthyology
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• v.34 no.1
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• pp.16-24
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• 2022

The eggs development and early life history of Sarcocheilichthys variegatus wakiyae was investigated. The adult fishes were collected in Yeongsangang River, Damyang-gun, Jeollanam-do, Korea, and their spawning inducement was carried by sex maturation hormone (Ovaprim) injections. Spawning amount was mean 31±3.5 Mature eggs were cicular in shape and mean 2.40±0.05 mm in diameter. Hatching period of the embryo was 230 to 240 hours after fertilization under water temperature of 22℃. The newly hatched larvae were 10.7±0.19 mm in total length (TL). 3 days after hatching, postlarvae was measured 12.0±0.13 mm in TL and the tip of the caudal fin was bent at 45°. 11 days after hatching, it was measured 14.6±0.13 mm in TL, and transferred to juvenile as the number of fins (iii7 dorsal fin, iii6 anal fin, i7 ventral fins) reached a constant number of each part.

• Korean Journal of Ichthyology
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• v.33 no.3
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• pp.167-176
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• 2021

This study was carried out to clarify the egg, larvae and juveniles development of Abbottina springeri. For the experiments, the matured adults were collected at the Seowon-cheon, Dangjin-si, Chungcheongnam-do, in Korea. The amount of spawning of female A. springeri was about 1,225~2,100 (1,662±437, n=10). The fertilized eggs were circular in shape and 1.05~1.13 (1.08±0.02, n=30) mm in diameter. The hatching time was required 72 hours to 80 hours after fertilization under water temperature of 22℃. The newly hatched larvae were 2.10~2.23 (2.16±0.04, n=10) mm in total length and had egg yolk in the abdomen but the mouth was not opened. At 5 days after hatching, the preflexion larvae were 3.19~3.30 (3.24±0.03, n=10) mm in total length and the most of yolk-sac was absorbed. At the 15 days after hatching, the flexion larvae were 4.97~5.30 (5.13±0.12, n=10) mm in total length and the tip of the caudal fin was began to bend upward. At the 25 days after hatching, the postflexion larvae were 8.97~9.60 (9.44±0.16, n=10) mm in total length and the tip of the caudal fin was bent at 45°. At the 35 days after hatching, the juvenile were 12.0~13.5 (12.7±0.53, n=10) mm in total length and all fin-rays (iii7 dorsal fin, iii6 anal fin, i7 ventral fins) were reached a constant number of each part.