• Development and Reproduction
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• v.10 no.1
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• pp.41-45
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• 2006

The spawning behavior of Liobagrus obesus was observed at Kumgang river, Yeongdong-gun, Chungcheongbuk-do from Apirl to July 2004. The fertilized eggs collected by dip net and skimming net were carried to the laboratory of Chonnam National University, and then egg, larvae and juvenils development were studied. Hatching of the embryo began about at 225 hrs 15 mins after morula stage in water temperature of $19.5{\sim}24.9^{\circ}C$(mean $22.8^{\circ}C$). The newly-hatched larvae were $7.30{\sim}7.90mm$(mean 7.66mm) in total length (TL), their mouth and anus were already opened with 14+28=42 myotomes. Sixteen days after hatching, the postlarvae were $13.00{\sim}14.05mm$(mean 13.48mm) TL, the yolk sac was completely absorbed. The juvenile stage was reached when all fin-rays were formed at 24 days after hatching, and $15.31{\sim}17.20mm$(mean 16.31mm) TL.

• Development and Reproduction
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• v.10 no.1
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• pp.47-54
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• 2006

The Tridentiger obscurus were collected of Ocheon-dong and Dolsan-do in Yeosu from Apirl to July 2003, and were carried to the laboratory to investigate their development of spawning habit, egg development, larvae and juveniles. The fertilized eggs were measured $0.86{\sim}1.07{\times}0.53{\sim}0.74\;mm$ in diameter. Hatching of the embryo began about 154 hrs 40 mins after fertilization in water temperature of $18.4{\sim}23.2^{\circ}C$(mean $21.2^{\circ}C$). The newly-hatched larvae were $2.72{\sim}2.87mm$(mean 2.83mm) in total length (TL), their mouth and anus were opened, and the yolk sac was completely absorbed. At 21 days after hatching, the postlarvae were $5.32{\sim}7.23mm$(mean 6.02mm) TL, and the tip of the caudal notochord was flexed $45^{\circ}$ upward. The juveniles stage was reached when all fin-rays were formed at 45 day after hatching, and $11.62{\sim}14.32mm$(mean 13.45mm) TL.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.1-8
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• 1989

In August, 1988, matured adults of devil stinger were collected from Jinhae Bay and Jaran Bay, Kyongsangnam-do, Korea and kept in the aquarium (1 ton) for spawning. The egg development was observed with the eggs laid in the aquarium of adult fish. The diameters of eggs ranged from 1.2 to 1.3 mm (n=6), and no oil globules were found in the eggs. The hatching took place from 26 to 29 hours after eight cells stage at the water temperature of $24.9-26.5^{\circ}C$. The newly hatched larvae were 2.47~3.10 mm in total length with xanthophore on the body and yolk sac. Myomere number was 13+16-17=29-30. Two days after hatching, larvae were 3.61-4.16 mm in total length, and 3 to 4 large spots of melanophore appeared on the large pectoral fin. Three days after hatching, larvae were 3.97-4.29 mm in total length, and the larvae absorved the yolk material completely to become post larvae with 4-5 rays of the pectoral fin. Six days after hatching, larvae attained 4.07-5.46 mm in total length, and 11 rays and 8-9 spots of melanophore were developed on the pectoral fin.

• Development and Reproduction
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• v.15 no.2
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• pp.121-131
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• 2011

The aim of this study was to investigate the egg development and the color change of Amphiprion melanopus, by the live food and thyroid hormone. After fertilizing, it took 168 h until hatching. The size of hatching larvae were $3.5{\pm}0.3$ mm, and some individuals had small yolk sac. As reaching the particular age, they underwent the color change (metamorphosis) - Days after hatching (DAH) 10: black, DAH 15~20: the 3 white stripes appear, DAH 30: the dorsal & the caudal white stripe begin to disappear. DAH 90: body color become red and orange, adult: cinnamon body color and a white stripe on head. - The group fed enriched Artemia with Tigriopus japonicus grew the faster than with only Artemia. The fin coloration of the one fed the only T. japonicus has a vivid red and orange color. $T_3$-treated group (4 ppm) grew the faster than the others (0, 2, 6 ppm). The size of the 6 ppm group was the smallest. The results suggest T. japonicus can be used as a supplement with rotifer and Artemia for the juvenile development and coloration. $T_3$ is considered to be involved in the metamorphosis and color formation of Amphipirion sp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.167-176
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• 1991

Sexual maturation of the bluespotted mud hopper, Boleophthalmus Pectinirostris(Linnaeus) was investigated histologically on the gonadal development, and studied by gonadosomatic index(GSI), egg diameter composition. Samples were collected in the intertidal zone of Wolyon-ri, Hoihyon-myon, Okku-gun, Chollabuk-do, Korea, from April to October in 1988 and from June to August in 1989. The ovary is a pair of sac-shaped organ. The testis is a pair of tubule-shaped organ and it is connected to the seminal vesicle which is located at the posterior end of the testis. In male and female, GSI began to increase from late May when the water temperature began to increase and reached the maximum value in June and July, respectively. It began to decrease from August, the highest water temperature season. Thereafter, maintained relatively low values until October. The annual reproductive cycle of this species could be classified into four sucessive developmental stages: growing stage$(April{\~}May)$, mature stage$(June{\~}early\;July)$, ripe and spent stage(late lune-early August), degenerative and resting stage$(late\;August{\~}March:\;the wintering\;period)$. According to the frequency distributions of egg diameters in the spawning season, Boleophthalmus Pectinirostris was species to spawn twice or more in the spawning season.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.396-415
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• 1992

To investigate identification of species distribution state, population density of plant parasitic nematodes and damaged state by parasitism of nematodes with soil samples taken from major cultivating area of medicinal herbs in Kyungbuk districts are summarized as follow; total species belonging to genera in families were identified from 43 different medicinal herbs. The dominant nematode species on medicinal herbs was Meloidogyne hapla by 55.6% of field infection. Damaged state by parasitizm of Root-knot nematode, M. hapla, M. incognita are severed 15 medical plant except P. japonica, infected field were in 54.5~88.0%, and highered in population densities of 2nd larvae, Gall, Egg sac. Percentage of yield-decrease were 57.8% in A. gigas, 49.1% in P.japonica. Lighten effect of M. spp. by cropping system were lowered in population density in Rice+Paeony than Paeony+Paeony in paddy field, and also lowered in Sesame+Paeony or one year fallowing after harvest Paeony than Red pepper+Pseony, Paeony+Paeony in upland field.

• Korean Journal of Ichthyology
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• v.35 no.2
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• pp.75-82
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• 2023

The samples used in this study were collected on two occasions (April 21 and May 16, 2021) from Liobagrus mediadiposalis and spawned egg masses located under rocks in Daeseocheon, Yeongdeok-gun, Gyeongsangbuk-do. Fertilized eggs ranged in size from 3.30~3.92 (average 3.57±0.19) mm (n=30), and it took 152~155 hours to hatch at water temperatures of between 17.0 and 20.0℃. Newly hatched larvae immediately post-hatching had a total length of 6.43~6.67 (6.55±0.07) mm (n=30), and were characterized by the retention of a yolk sac and an incompletely open mouth and anus, consistent with the yolk. On the 9 days post-hatching, the postflexion larvae had grown to length of between 11.0~13.8 (12.3±0.70) mm (n=30), and the caudal bone at the tip of the tail was bent upwards at an angle of 45°, thereby indicating the transition to the late larval growth stage. On the 16 days post-hatching, the total length of juvenile had increased to between 15.8~18.2 (16.8±0.77) mm (n=30), and the number of fins reached a fixed number of 8 dorsal, 17 anal, and 8 pelvic fins. On the basis of the findings of this study, we were able to confirm differences in the size of hatching larvae and fin mottle patterns in the early life history of related species.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.253-262
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• 2023

This study compared the results of observing the early life history of Gymnogobius urotaenia, which lives in Hwangbocheon Stream, an inflow stream on the east coast, with the differences between fish of the same Gobiidae fishes. In May 2022 and 2023, fertilized eggs and brood stork scattered under rocks were captured twice in Hwangbocheon Stream. The spawning amount was 827~1,540 and the orchid was a elliptical in shape with a size of 3.21×1.07 mm. The stage of ovulation observed in the laboratory was 16 cells, and hatching began after 193 hours. The breeding water temperature range was 18.8~19.3℃. Newly after hatching larvae, the yolk sac with a total length of 3.84~4.33 (average 4.10±0.17, n=30) mm, and the anus was not open. 6 days after hatching of incubation, the total length was 5.32~6.11 (average 5.67±0.25, n=30) mm, absorbing all egg yolk and transitioning to the preflexion larvae, ingesting food, and developing a keynote on the tail fin. 15 days after hatching, the end of the urostyle end was completely bent at 45° with a total length of 7.33~8.52 (average 7.81±0.46, n=30) mm and transitioned to postflexion larvae, and melanophore developed throughout the body. 38 days after hatching, the total length is 22.1~26.1 (23.8±1.36, n=30) mm and the number of fins (6 first dorsal fins, 11 second dorsal fins, and 11 anal fins, 12 ventral fins) is all the number of fin base became integer and transferred to the juvenile. As a result of the study, it was possible to distinguish the melanophore of postflexion larvae of G. urotaenia from other postflexion larvae Gobiidae fish in that they were distributed throughout the body of half the body and tail.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.478-484
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• 2008

To elucidate the spawning behavior and early life history of Liobagrus mediadiposalis, mature male and female fish were collected from a branch of the Seomjin River. Spawning was induced by injecting hormones, and then the spawning process and development of fertilized eggs, larvae, and juveniles were observed. Observations of spawning behavior showed that the female established a territory and built a spawning nest, and frequently pressed on the upper ventral part of the male to release her eggs. When spawning was finished, the fish supplied fresh water to the egg mass using their pectoral and caudal fins. Hatching began 189 h 20 min after fertilization at $21.5-23.5^{\circ}C$ (mean $22.7^{\circ}C$). The mean total length (TL) of newly hatched larvae was 7.18-7.39 mm (mean 7.31 mm). Their mouth and anus were already open and they had 14+24=38 myotomes. Eighteen days after hatching, the larvae were 12.71-13.79 mm (mean 13.27 mm) in TL and the yolk sac was absorbed completely. At 35 days after hatching, when all the fin-rays had formed, the juveniles were 15.84-17.92 mm (mean 16.33 mm) in TL.

• Journal of Aquaculture
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• v.12 no.4
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• pp.255-266
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• 1999

The early development, growth, and morphological changes of Tiger puffer Takifugu rubripes are described on the basis of a seres of a series of reared specimens. Detailed o수 the early developmental stages are illusrtated withe special reference to morphological transformation. Egg and sperm of puffer fish Takifugu rubripes were obtained from mature adults under natural conditions, ferilized artificially and incubated in the laboratory. The incubation period of fertilizd eggs was 160 to 180 hours at a temperature of $15.1~ 18.0^{\circ}C$. Larvae were fed successively with rotifer, Artemia nauplii and artificial food for 90 days. The mean total length of newly-hatched larvae was about 2.8mm. Mouth opening occurred on the 1- day yolk-sac larvae and initial feeding was observed on th 4-5 days after hatching . The morphological transitions from the larvae to juvenile and juvenile and juvenile to young stages occurred when fish reached about 10mm in total length(about 30 days after hatching) and about 32mm in total length(about 60days after hatching) , respectively. The coefficient of variation in total length distribution increased with growth. Following the appearance of its peak at the size of about 18mm in total length, the coefficient value declined. Many changes in proportion of the body parts to total length were observed at about 9~10mm and 30~33mm in total length, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. Also one big morphological change was observed at about 18mm in total length that divide the juvenile stage into two sub-stages.