• Development and Reproduction
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• v.2 no.1
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• pp.81-87
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• 1998

A scanning electron microscopic study on the glochidial encystment and excystment during the development of Anodonta arcaeformis flavotincta on Carassius auratus, a common natural host fish, was carried out. The glochidia were attached to the fins, buccal cavity and gills of the host fish within 30 minutes. In this study, the fins of host fish infected with the glochidia were examined in a time series. The attachment rates of the glochidia on the pectoral fins, caudal fin and pelvic fins of the host fish were 30%, 22%, and 17%, respectively. The glochidia which attached to the fish became encysted within 27 hrs. The process of encystment progressed slowly. Ti took 24 to 27 hours in the formation of the primary cyst, and after 5 to 6 days, the larvae was covered completely with the epithelial cels of the host tissues. The process of detachment of juvenile clam was observed on the 8th day after host infection. Most of the juvenile clams have sloughed from the cyst of the host within 15 days. No significant size difference was observed in the glochidia and the juvenile which were found before attachment and after detachment from the cyst of the host fish.

• Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.109-116
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• 2013

Eighteen specimens of juvenile Mugilidae were collected in October 2012 from the southern coastal waters of Jeju Island, and identified based on analysis of their mitochondrial DNA16S rRNA sequences. Seventeen specimens of Oedalechilus labiosus and a single specimen of Ellochelon vaigiensis were found, constituting a new record for these species among Korean ichthyofauna. O. labiosus is identified by the angle at the posterior end of its mouth, which contains a round notch, a darkish dorsal margin of the pectoral fin, the presence of 33-36 lateral line scales, and 23-24 vertebrae. E. vaigiensis is identified by dark dorsal and pectoral fins, the presence of 26 lateral line scales, and 25 vertebrae. The proposed Korean name for Oedalechilus is 'Sol-ip-sung-eo-sok' and that for Ellochelon is 'Nup-jeok-ggo-ri-sung-eo-sok'. The proposed Korean names for the species are 'Sol-ip-sung-eo' and 'Nup-jeok-ggo-ri-sung-eo' for O. labiosus and E. vaigiensis, respectively. We present a key for identification of the Mugilidae family of species from Korea, and include these two newly recorded species.

• Korean Journal of Ichthyology
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• v.36 no.1
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• pp.1-9
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• 2024

This study investigated the early life history of the Boleophthalmus pectinirostris living in the southern coastal Yeoja-man and compared the results with the same Gobiidae fishes. The brood stork used in the study were captured with bare hands in the tidal flats of Beolgyo-eup, Jeollanam-do, in June 2015. The amount of spawning was 411~11,688, and the eggs were short oval and the size was 1.40×0.72 mm. The time of hatched took 91 hours and 35 minutes at a water temperature of 25~27℃. Newly hatching larvae, the yolk sac had a total length of 3.02~3.31 (average 3.17±0.08, n=30) mm and did not eat rotifer. 4 days after hatching, the total length was 3.31~3.52 (3.43±0.07, n=30) mm, and as the mouth and anus opened, the fish transitioned to the preflexion larvae and fed. 14 days after hatching, the total length was 5.06~5.25 (5.16±0.06, n=30) mm, and the distal end of the vertebra was completely bent at 45° and the transitioned to the postflexion larvae. 41 days after hatching, the total length was 14.3~16.8 (15.4±0.85 mm, n=30), and the number of fins reached an integer of 5 first dorsal fins, 26~27 second dorsal fins, 24~27 anal fins, and 6 ventral fins, and the transitioned to the juveniles. As a result of the study, star-shaped melanophore were deposited from the front of the pectoral fin to the base of the caudal fin, which distinguished them in form from other postflexion larvae of Gobiidae fishes.

• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.42-47
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• 1991

A suspected intergeneric hybrid cross between Pungtungia herzi and Pseudopungtungia nigra was collected at the Ungcheon River. Overall hybrid index did not show the hybrid connection clearly, but the most striking key character between two genus, pigmentation on the all fins except pectoral, the shape and position of the mouth part appeared to show the intermediary. So this specimen was thought to be an intergeneric natural hybrid which merits further study.

• The Korean Journal of Zoology
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• v.27 no.1
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• pp.49-55
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• 1984

Cobitis choii, n. sp. is descirbed from 14 specimens (55.1-69.7 mm SL) collected from sand bottoms in the Miho-cheon stream, Chungcheongbug-go province, Korea. C. choii is compared with the specimens of C. koreensis, C. granoei, and C. taenia lutheri. The new species differ from them in the serrated lamina circularis at the base of pectoral fins in male, the rounded spots and small scales on the body sides, and slender caudal peduncle.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.465-476
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• 1993

Rockfish, Sebastes inermis is a ovoviviparous fish distributed around the coastal waters of Korea and Japan. Naturally beared larvae obtained from female fish kept in the aquarium were reared for three months in the laboratory. The naturally healed larvae were 6.05mm in average total length(TL) with $8+18{\sim}19=26{\sim}27$ myomeres. Melanophores were distributed on the top of head, around the intestine tube and on the dorsal and ventral margins of the tail, but none on the pectoral fins. The larva(7.1mm in TL) consumed all the yolk and oil globule, in 7 days after bearing, and jaw bones were more rapidly ossified than vertebrae and cranium. In 21 days after bearing, the larvae averaged 8.50mm in TL and the caudal notochord flex $45^{\circ}$. Fin development in S. inermis larvae proceeds in the following sequence: caudal, pectoral, dorsal, anal and ventral fin. Individuals $17.6{\sim}20.8mm$ in TL($65{\sim}69$ days after bearing) are regarded as the juvenile stage. All fins bones was nearly completed in this stage.

• Korean Journal of Environmental Biology
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• v.18 no.3
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• pp.323-330
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• 2000

Early life history and spawning for Odontobutis interrupta were observed in the laboratory during May-August 1999 with a condition of natural habitats in the field. Optimal water temperature for spawning was between 17.5 and 22.$0^{\circ}C$ and appropriate water depth and current velocity in the natural habitat ranged 0.3-0.6 m and 0.1-0.3 m/sec, respectively. Ovary maturation index peaked at about 100mm in the total length and their values gradually decreased after the size. Male fishes showed a territory and courtship behavior to adult females and the males frequently pushed upper-ventral part of females for egg releases. After females spawned, the males guarded the egg masses and supplied dissolved oxygen using pectoral fins. According to observation of egg development in the laboratory, blastodisc formed in 1hr 17 min after the fertilization, cleavaging at 36-minute interval regularly. Blastulation occurred in 7 hr 12 min after the fertilization, with gastrulation after 11 hr 11 mins and formation of york plug after 32 hr 48 min. Embryo was formed in 33 hr 45 min after fertilization and optic vesicles appeared in 47 hr 27 mins when 30-31 somites were formed. Cardiac primordium was formed in 65 hr 15mins and its beat averaged 44- 48 time/min. Pectoral fins were formed in 138 hr 40 min, air-bladder and black vesicles were observed in lower portion of young fish. Embryo hatched from she-11 membrane after about 10 days and juvenile was 5.8$\pm$0.2mm in total length 3.0$\pm$0.5mg in weight.

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.100-110
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• 2001

Taxonomic review of the five flyingfishes, Parexocoetus mento (Valenciennes), Cheilopogon agoo (Temminck et Schlegel), Cheilopogon heterurus doederleini (Steindachner), Cheilopogon cyanopterus (Valenciennes), Hirundichthys oxycephalus (Bleeker) were carried out based on samples collected from the South sea and around sea of Jeju Island of Korea from 1996 to 1998. Parexocoetus mento (Valenciennes) and Cheilopogon cyanopterus (Valenciennes) were revealed as the unrecorded species in Korea, which were named as "Men-to-hwang-nal-chi" and "Ki-geom-nal-chi" respectively. Parexocoetus mento is differed from P. barchypterus in having no chin barbels in juveniles, and Cheilopogon cyanopterus is distinguished from C. agoo in the branched form of pectoral fin rays and from C. heterurus doederleini in the numbers of the dorsal fin ray and the color of pectoral fins.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.2
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• pp.228-242
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• 2023

We examined the osteological development of the cranium, visceral skeleton, pectoral girdle, vertebral column, fins, and pterygiophore of small yellow croaker Larimichthys polyactis cultured at the Jeju Fisheries Research Institute. At 5.89 mm NL (notochord length), the larvae already had ossified frontal and basioccipital bones, parasphenoids, and vomer in the cranium. All elements of the visceral skeleton except the metapterygoid were ossified at 5.89 mm NL. Preorbital bone was ossified at 8.11 mm SL (standard length), and suborbital bones were ossified at 12.90 mm SL. In the vertebral column, ossification proceeded from the first to last centrum. The urostyle ossified at 7.41 mm SL. The caudal skeleton ossified at 6.78 mm NL, along with three hypural bones. In the pectoral girdle, the cleithrum, supracleithrum, postcleithrum, and post-temporal bones ossified at 5.89 mm NL. Caudal fin ossification began at 6.19 mm SL and was complete at 7.16 mm SL. Dorsal and anal fin ossification began at 7.16 mm SL and was complete at 8.62 mm and 8.11 mm SL, respectively. Anal and dorsal pterygiophore bone ossification was complete at 9.86 mm and 11.54 mm SL, respectively, and that of the supraneural bones was complete at 9.60 mm SL.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.725-730
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• 2015

We observed yellow catfish Pelteobagrus fulvidraco fingerlings cultured in land ponds in Korea swimming in a corkscrew spiral pattern while hanging head-up and tail-down at the water surface, before eventually dying. Externally, these fish displayed “hole in the head” disease, pale gills, and hemorrhages in the base of the pectoral and caudal fins; internally they had liver hemorrhages and kidney discoloration. The bacterium Edwardsiella ictaluri (YCK-01 and YCL-01) was identified in the kidneys and livers of diseased fish via phenotypic characteristics and PCR analysis using the ictaluri-specific primers IVS (an intervening sequence) and IRS (the inter-ribosomal spacer). Infectivity challenges by intraperitoneal and immersion routes showed that a representative bacterial strain (YCK) exhibited strong virulence to yellow catfish, with an LD₅₀ of 3.2×10⁴ CFU/fish and 2.5×10⁶ CFU/mL, respectively. This is the first report of E. ictaluri infection in yellow catfish from Korea.