• Journal of Ecology and Environment
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• v.29 no.3
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• pp.277-286
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• 2006

Population ecology of Cobitis tetralineata was examined at Churyeong Stream, Seomjin River, Korea. C. tetralineata inhabited on the sand bottoms with $10{\sim}20cm/see$ in current velocity, and $30{\sim}150cm$ in water depth. This species was active on the sand during the daylight hours from March to October, but they hibernated in the inside of the sand during the winter season. Sex ratio of female to male was 1:0.57, and female was $20{\sim}30mm$ (TL) larger than male. The age group of C. tetralineata (female) population showed that the $20{\sim}40mm$ group is 0+ years old, the $45{\sim}65mm$ group 1+ years old, the $65{\sim}90mm$ group 2+ years old, and the group longer than 90 mm over 3 years old. Males $13{\sim}14$ months old after hatching had lamina circularis at the base of its pectoral fin as a secondary sexual character. And in its spawning season, lateral color pattern of male was changed as a sexual dimorphism. The spawning season may be from late June to middle July, $22{\sim}26^{\circ}C$ water temperature. The average number of mature eggs in ovary was about $1,288{\pm}583(474{\sim}2,976)$, egg diameter was about $0.98{\pm}0.1mm$. C. tetralineata fed mainly on Chironomidae, Arcellidae, Branchioda and Algae. The feeding rate was the highest in April and September, but they did not fed in the winter.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.380-386
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• 1986

Snailfish, Liparis tanakai (Gilbert et Burke) is widely distributed in the coastal waters of Korea and Japan. On December 21, 1985, fertilized eggs of the fish were collected from the coastal waters of Saryang-do island, Kyongsangnam-do, Korea, and the eggs were incubated and the larvae reared at a mean water temperature of $9.2^{\circ}C$ in the laboratory. The fertilized eggs of this species are demersal, adhesive and spherical in shape, measuring $1.68{\sim}1.78mm$ (mean 1.72mm, n=30) in diameter, containing about 20 oil globules. Hatching took place 21 days after blastula stage. During the incubation period water temperature fluctuated between $8.1^{\circ}C\;and\;11.8^{\circ}C$. The newly hatched larvae were $5.70{\sim}6.41mm$ (mean 6.10mm, n=30) in total length with $7{\sim}9$ (abdominal) and 36 (caudal) myomeres. Many melanophores were distributed on the large pectoral fin, yolk sac and peritoneum. Twelve days after hatching, the larvae attained $5.85{\sim}6.46mm$ in total length, and at this time the larvae absorbed the yolk almost completely. Melanophores appeared on the snout and the posterior part of head.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.308-316
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• 1987

The flying fish, Prognichthys agoo, is widely distributed in the coastal waters of south-eastern Korea. On July 14, 1986, mature adults of flying fish were captured from U-do, Cheju-do. The eggs were stripped and fertilized by the wet method on the ship. The mature eggs are demersal and adhesive with 30-40 filaments. The egg diameter varied from 1.42 to 1.58 mm. The water temperature throughout incubation ranged from 23.70 to $27.82^{\circ}C$, and salinity was maintained at $30.75-33.76\%_{\circ}$. The hatching took place in 174 hours after fertilization. The newly hatched larvae measured 4.75-5.25 mm in total length possessing yolk sac and about 45-46 myotomes. The larvae cultured for ten days after hatching reached 11.45-12.60 mm in total length and entered the juvenile period of life. Twenty days after hatching, the juveniles measured 20.01 mm in mean total length, and the scales were formed behind the pectoral fin.

• Korean Journal of Ichthyology
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• v.18 no.1
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• pp.27-35
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• 2006

During spawning season of female in a Korean oily bitterling, Acheilognathus koreensis, the ventral region near the base of the pectoral fin becomes to be protruded outward of body and enlarged. This ventral process consists of both organs as rectum (vent) and inner ovipositor. The rectum consists of mucosa, lamina propria-submucosa, muscularis, and squamous epithelial layer (peritoneum=serosa) surrounding them. The mucosa contains numerous mucous cells meaning acid mucopolysaccharides in nature. The inner ovipositor is similar to that of the rectum, but the mucosa have no mucous cell, unlike that of the rectum. Whereas, the outer ovipositor has a straight and long tube which are not connected with the ventral process any more. The outer ovipositor was similar to the structure of the inner ovipositor in the ventral process. However, the outer ovipositor has no muscularis, and consists of three layers: mucosa, lamina propria-submucoa, and squamous epithelia. The outer ovipositor without the muscularis seems serves as a tube that eggs discharged from the outer ovipositor allow to send inside mussel, unlike that of the inner ovipositor performing rhythmic contractions of the layers of the muscularies for propelling to the matured oocytes to the outer ovipositor.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.148-154
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• 2021

Two specimens (1770~1850 mm disc width) of Mobula thurstoni, belonging to the family Myliobatidae, order Myliobatiformes, were first collected from the central coast of the Southern Sea of Korea in September 2018. This species is characterized by an anterior margin of disc with double curvature, a white-tipped dorsal fin, and the absence of a caudal spine. This species is morphologically similar to Mobula kuhlii, but has an anterior margin of pectoral fins with a double curvature and the dorsal coloration is bluish black rather than white. In addition, M. thurstoni was well distinguished from M. kuhlii as determined by mitochondrial DNA 16S rRNA sequences with genetic distances ranging from 0.030 to 0.069. The Korean name 'Mae-kkeun-kko-li-jwi-ga-o-li' is proposed for the species M. thurstoni.

• Korean Journal of Ichthyology
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• v.30 no.4
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• pp.205-216
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• 2018

Taxonomic review of the genus Saurida, belonging to the family Synodontidae, was conducted based on three species (S. macrolepis, S. microlepis and S. wanieso) collected from Korea between 1994 and 2017, and one species (S. elongata) loaned from Japan. S. wanieso can be readily distinguished from S. tumbil by following characteristics: outer palatine teeth (2 rows in S. wanieso vs. 3~4 rows in S. tumbil) and pectoral fin length (reaching to pelvic - dorsal line in S. wanieso vs. not reaching to pelvic - dorsal line in S. tumbil). In counts, the four Saurida spp. are well distinguished: number of lateral line scales (48~50 in S. macrolepis vs. 54~58 in S. wanieso vs. 61~62 in S. elongata vs. 63~70 in S. microlepis), vertebrae (47~49 in S. macrolepis vs. 51~53 in S. wanieso vs. 57~59 in S. elongata vs. 62~64 in S. microlepis). The present study suggests S. undosquamis and S. tumbil must be absent in Korean waters, and also S. elongata may be rare or absent in Korean waters. Here we use the Korean name, "tum-bil-mae-tung-i" for S. wanieso, following Yamada et al. (1995) who treated Korean S. tumbil as S. wanieso.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.305-312
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• 1997

Juveniles of black seabream, Acanthopagrus schlegeli were fed with the diets containing 0, 10, 20, 50 and 100 ppm of 3,5,3'-triiodo-1-thyronine $(T_3)$ respectively to assess the effect of this hormone on skeletal development and the change of physiological conditions for 50 days. $(T_3)$ treatment lasted for initial 40 days. Fish were fed the prescribed diet by hand to satiation in $2\~4$ times per day. After an initial 40 days period, skeletal development and abnormality were examined, and after a 50 days period, food intake, hepatosomatic index (HSI), thyroid cell height (TCH) and body proximate composition were also examined. Although toed intake was not different among 0, 10 and 20 ppm, the food intake of black seabream fed with the diets containing 50 and 100 ppm of $T_3$was significantly lower than those of 10 ppm. After the initial 40 days of $T_3$ administration, $T_3$ increased the relative growth of operculum, head, caudal fin and pectoral fin to body length, resulting in severe morphological abnormalities at the highest dose. Black seabream treated with 50 and 100 ppm of $T_3$ had abnormal shapes such as lordosis and opercular curl. The HSI parameters were reversely correlation with the dietary concentration of $T_3$. After the initial 40 days of this experiment, atrophy of thyroid gland was observed in fish administered with 50 and 100 ppm of $T_3$. On the 50th day of this experiment, atrophy of thyroid gland was observed only in the group administered with 100 ppm of $T_3$, and no difference was observed on TCH among the rest fours of experimental groups. At the end of the experiment the whore body proximate analyses indicated that there were significant effects of $T_3$ level on moisture, protein, lipid and ash contents.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.3
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• pp.124-132
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• 2006

We have investigated morphological development with growth and survival rates of juvenile for 158 days after parturition to get a basis data in the way of establishment of breeding techniques in the common seahorse species of Barbour's seahorse, Hippocampus barbouri. At 1 day after parturition, seahorse larvae were $8.82\sim10.36mm(mean\;9.48{\pm}0.69mm,\;n=4)$ in standard length (SL) with 17 dorsal fm rays, 14 pectoral fin rays and 4 anal fin rays. At 20 days after parturition, the size of seahorse larvae were $14.37\sim15.79mm(14.97{\pm}0.62mm,\;n=4)$ in SL, snout of seahorse larvae became slender was long, and body was coloration to the full as adult seahorse. At 41 days after parturition, seahorse larvae were grew $20.14\sim24.89mm(22.89{\pm}2.22mm,\;n=4)$ in SL with development of several spines in coronet, and their have 11 trunk rings and 35 tail rings. At 158 days after parturition, seahorse were grew to $59.07\sim63.76mm(61.42{\pm}3.32mm\;n=2)$, and head length (HL), trunk length (TrL) and tail length (TaL) were composed respectively $19.1{\pm}0.3%,\;25.2{\pm}0.7%$ and $55.8{\pm}0.3%$ of SL. In this time, survival rate is 15.6%.

• Development and Reproduction
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• v.11 no.2
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• pp.127-135
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• 2007

In order to monitor the developmental features of embryos, larvae, and juveniles of Konoshiro Gizzard Shad Konosirus punctatus, the fertilized eggs were gotton using artificial insemination. Konosirus punctatus were caught in Mankyung-myeon, Kimjae, Jeollabuk-do at June of 2004, and experiments were carried out in Ichthyology laboratory in Chonnam National University. Konosirus punctatus spawned draft egg from March to June. The fertilized eggs were cultured in $19.0{\sim}23.0^{\circ}C$(mean, $21.2^{\circ}C)$. The eggs had spherical shape and the diameter is $1.14{\sim}1.34\;mm$(mean, 1.21 mm). The lens began to appear from 35 hr 53 min after fertilization. At the moment, the movement of larvae was more active, and the tail was separated completely from yolk, the heart had forms, and melanophore appeared. Hatching was observed from 37 hr 10 min after fertilization. The total length of the hatched larvae was $4.26{\sim}5.30\;mm$(mean, 4.96 mm), but the mouth and anus were not opened at the time when the larva had yolk sack, and had $22{\sim}27$ myometium, and the anus located just abdominal front of the tail fin, and melanophore accumulated in the eye. Post-larvae used yolk completely after 2 day of hatching, and the total length was $4.96{\sim}5.74\;mm$(mean, 5.24 mm). From 16 days after hatching, the tail had curved tail end, and appeared the stems for pectoral, dorsal, and caudal fins. At 53 days after hatching, the total length of post-larvae was $27.11{\sim}34.09\;mm$(mean, 30.11 mm), and the frontal part of head developed like an adult one. At this time, fins and body are transferred to those of adult Konosirus punctatus. Fishes have a different shape and location of melanophore even in the same family. This research was tried to elucidate the early developmental features of Konosirus punctatus, together with species-specific pattern of melanophore.

• 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.