• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.138-143
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• 2022

Based on three specimens (50.6~67.7 mm SL) collected from the southern coastal waters of Jejudo Island, Oxycheilinus bimaculatus was described as the first record from Korea. They were characterized by having two small dark spots behind eye on head and body posterodorsally, a rhomboid caudal fin with elongated central rays and produced uppermost ray as a filament in terminal male, six predorsal scales, and two scale rows on cheek. We proposed a new Korean name, "Du-jeom-gin-ju-dung-i-nol-rae-gi", for the species referring to having two dark spots on head and body.

• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.119-126
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• 2022

Here, we present the first morphological description of a larval Naso hexacanthus (5.2 mm in body length) from the East China Sea identified by cytochrome c oxidase subunit I (COI) barcoding. The larva had a kite-shaped body with long serrated first spine of dorsal and anal fins. There were four melanophores on the base of the anal fin, dense melanophores on the caudal peduncle, and scattered melanophores on the surface of the brain. There was one small spine on the snout and behind each eye, with serrations on the head, top of the eye, inner- and outer-preopercle, and on the lower part and side of the opercle. The morphological characteristics of larval N. hexacanthus identified by COI barcoding will be useful for species identification of larval fish.

• Korean Journal of Ichthyology
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• v.35 no.3
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• pp.201-206
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• 2023

A single specimen of the genus Plectorhinchus (Family: Haemulidae) was collected from the coastal waters around Jejudo Island on November 1, 2017 by a longline. The specimen was identified as Plectorhinchus vittatus by the morphological characters as follows: eight black vertical stripes on the body, scattered polka dots on the dorsal, anal and caudal fins. It is clearly distinguished from the congeneric species, P. lineatus, which is morphologically very similar to P. vittatus, in the number of gill rakers, stripes on the abdomen, and black patterns on the base of the pelvic fin. In this study, the occurrence of this species has been newly revealed at higher latitudes, suggesting the expansion of the northern distribution limit. Following Lee et al. (1999), we propose its Korean name as "Chu-sa-eo-reum-dom".

• Fisheries and Aquatic Sciences
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• v.26 no.12
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• pp.752-761
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• 2023

Genetic diversity serves as the basis for selecting and genetically enhancing any culturable species in aquaculture. Here, two different strains of wild (River Ravi and River Kabul) and six captive-bred strains of Labeo rohita from various provinces were se- lected, and genetic diversity among them was evaluated using three different microsatellite markers, i.e., Lr-28, Lr-29, and Lr-37, and one mitochondrial CO1 (Cytochrome c oxidase subunit 1) gene. Different strains of L. rohita were collected, and part of their caudal fin was cut and preserved in ethanol for DNA extraction and determination of genetic diversity among them. Results in- dicated that selected markers were polymorphic with polymorphic information content (PIC) content values above 0.5 with the highest in Lr-28 followed by Lr-29 and then Lr-37. The observed heterozygosity (Ho) of all strains was higher (Avg: 0.731) but less than the expected heterozygosity (He). Moreover, TMs and WRs showed the highest He, while TKs showed the lowest, He. Over- all, inbreeding coefficient (FIS) values observed for all strains with selected markers were positive. The DNA barcoding with the CO1 gene revealed genetic variation among various strains, as demonstrated by the clades in the phylogenetic tree separating the strains into two distinct clusters that then divided into sub-clusters. In conclusion, TMs showed the highest heterozygosity as compared to other strains. Overall results provide the baseline data for the initiation of the genetic improvement program.

• Korean Journal of Ichthyology
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• v.4 no.2
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• pp.1-25
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• 1992

Taxonomic study of the five species (Acanthogobius elongata, A. flavimanus, A. lactipes, A. luridus and Synechogobius) from Korea was carried out based on morphometric, cephalic sensory canal and ecological characters. Taxonomic revision and classificational keys are provided. Synechogobius hasta is easily distinguished from four species of the genus Acanthogobius in eleven characters, i. e., the number of dorsal and anal fin rays, the transverse scales, the vertebral numbers, the formula of interneural spine of the first dorsal fin, the number of interhemal spine anterior to the first hemal spine, the number of epipleural and pleurals, the ratio of caudal peduncle length, the ratio of caudal peduncle depth and the regular variations in the ratio of body parts with the body length. In the genus Acanthobobius, A. elongata is distinguished from other 3 congeneric species in the ratio of body parts and the oculoscapular sensory canal. Moreover, A. flavimanus differs from other 3 congeneric species in the lateral scales, the transverse scales, the number of predorsal scales, the vertebral number, the number of epipleural and pleurals. Sensory papillae rows of S. hasta is not similar that of the genus Acanthogobius in having a singular sensroy papillae rows. A. elongata has no oculoscapular sensory canal D and A. flavimanus has transverse sensory papillae in cheek, and these are one of the unique characters distinguished form other congeneric species. In the spawning period inferred from gonadosomatic index, A. elongata varied from late March to late June ; A. flavimanus, January to April ; A. lactipes, May to September ; A. luridus, early May to early July and S. hasta, early March to early May.

• Korean Journal of Ichthyology
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• v.36 no.2
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• pp.120-128
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• 2024

In this study, the characteristics of the early life history were investigated for the Hypomesus nipponensis in the west coast Daeho Bay. Egg's were adhesive eggs that had the property of sinking in water in a circular shape. The size of mature eggs was 0.52~0.66 (average of 0.59±0.03, n=30) mm. The hatching time took 140 hours at a water temperature of 22~23℃. Immediately after hatching, the yolk sac larvae was 4.78~5.60 (average of 5.25±0.26, n=30) mm in total length, and the mouth and anus were not completely opened. On the 7 days after hatching, the preflexion larvae was 5.91~6.64 (6.32±0.21) mm in total length, and the mouth and anus were opened, and feeding activities were started. On the 25 days after hatching, the flexion larvae was 9.70~12.3 (10.2±0.63) mm in total length, and the end of the spine at the tail end began to bend upward. On the 42 days after hatching, the postflexion larvae was 14.1~18.8 (16.9±1.44) mm in total length, and the end of the spine at the tail was completely bent at 45°. On the 56 days after hatching, it reached the integer with 10 dorsal fins, 16 anal fins, 7 ventral fins, and 19 caudal fins. According to the study, there were spot-shaped melanophore vesicles under the pectoral fins during the incubation period, the different positions of the egg yolk compared to the battlefield, the deposition of melanophore vesicles on the back and under the body of the caudal part during the postflexion larvae period, and the absence of melanophore vesicles on the torso between the head and the starting point of the dorsal fin. It was distinguished from related species in that melanophore vesicles were deposited in one row from the back of the body to the caudal part during the juvenile period.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.82-89
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• 2013

The spawning behavior, development of eggs and larvae of the Five striped damselfish, Abudefduf vaigiensis were studied. The Five striped damselfish were caught at Dolsan Island, Yeosusi, Jeollanamdo from May in 2011. As a result of observation, male fish attracted female after cleaning the rock. Female left after spawning and male protected their eggs until they had hatched out. The fertilized eggs were elliptical in shape (mean long diameter: 1.06 mm; mean short diameter: 0.55 mm) and transparent. Larvae hatched at 53 hrs after fertilization in $24.5{\sim}26.5^{\circ}C$(mean $25.0^{\circ}C$). The newly hatched larvae were 2.55~2.86 mm (mean 2.71 mm, n=10) in total length and their mouth and anus were already opened. They began to eat rotifer and transformed to postlarva stage. 3 days after hatching postlarva was measured 2.74~2.97mm(mean 2.84 mm, n=10) in total length. 10 days after hatching postlarva was measured 3.85~4.20mm(mean 4.00 mm, n=10) in total length with dosal fin rays IV-5; ventral fin rays I-3; caudal fin rays 1~2.

• Korean Journal of Ichthyology
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• v.13 no.3
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• pp.161-165
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• 2001

Artificial fertilization (dry method) of mature right-eye flounder, Limanda yokohamae (female : 25.1~30.4 cm in total length (TL), male : 24.5~28.5 cm in TL), obtained from the fish market in Dolsan-do, Yosu was performed in the Fisheries Exhibition. Hatched larvae and juveniles were reared to describe their morphological development. Newly hached larvae attained 3.13~3.42 mm in TL. Their eyes were yellowish brown and their mouth and anus were not yet opened. Three to six days after hatching the larvae attained 3.35~4.61 mm in TL. Their mouth and anus were open and the yolk sac was almost absorbed. Feeding activity increased as the mouth became larger. At 25 days, the larvae attained 5.47~5.91 mm in TL. The caudal notocord was flexed $45^{\circ}$ upward. At 35 days, the larvae attained 6.83~7.60 mm in TL. Rays of the dorsal and anal fins were formed, and the left eye was moved slightly to the right side of the head. At 55 days, the juveniles attained 9.38~11.73 mm in TL. The left eye was moved completely onto the right side. All of the fins had complete set of the fin rays, and the juveniles spent most of the time on the bottom resting on their blind side (D. 68~70 : A. 50~52 : P. 11: V. 6 : C. 18~19).

• Korean Journal of Ichthyology
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• v.27 no.2
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• pp.71-77
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• 2015

Morphological changes in eggs and larvae of spotted knifejaw, Oplegnathus punctatus were observed by cultivation of fertilized eggs to juvenile stage. Fertilized egg was demersal and transparent. The egg has one oil glouble and its size ranged 1.01~1.15 mm ($1.08{\pm}0.10mm$; $mean{\pm}SD$, n=20). Culture chambers were maintained $22.5{\sim}24.5^{\circ}C$ in water temperature and 33.5~34.5ppt in salinity. It took 25 mins from fertilization to the blastoderm stage, 55 mins to 2 cell stage and 20 hrs 50 mins to hatching. Newly hatched yolksac larvae ranged 2.59~3.02 mm ($2.81{\pm}0.25mm$, n=5) in total length, and mouth and anus were not still open. Yolk and oil globule were absorbed 2 days after hatching (DAH). Flexion larvae in 12 DAH ranged 3.02~3.07 mm TL ($3.04{\pm}0.04mm$), and the caudal fin grew to fan-shaped, melanophores appeared on top of digestive canal.

• Development and Reproduction
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• v.12 no.2
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• pp.133-139
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• 2008

The eggs of Luciogobius grandis attached beneath the small stone were collected at Ocheon-dong, Yeosu-city from February to May, 2006. We carried them to the laboratory of Chonnam National University to investigate their development. The fertilized eggs were elliptical in shape (mean long axis: $2.06{\pm}0.23\;mm$; mean short axis: $0.74{\pm}0.04\;mm$) and transparent. There were filaments on the egg membrane. Their hatching was occurred at 120hrs 54mins after the morula stage at $18.4{\sim}21.0^{\circ}C$ (mean $19.4^{\circ}C$). The newly hatched larvae were $3.30{\pm}0.07\;mm$ (n=30) in total length (TL), with $34{\sim}36$ myotomes, and their mouth and auns were already open. Their melanophores were appeared over the gas globule, around the anus and a part of caudal peduncle. At 9 days after hatching, the larvae was $5.06{\pm}0.18\;mm$ (n=30) in TL and transformed to postlarval stage with yolk absorption. At 29 days after hatching, the larvae attained full fin ray count and reached the juvenile stage with $11.46{\pm}0.12\;mm$ (n=30) in TL.