• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.18-26
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• 2018

We investigated to egg development and early life history of Tribolodon brandtii in the Korean peninsula. The fertilized eggs of the T. brandtii were slightly adhesive and separated with a yellow yolk and no oil globule, and they was an average of $2.4{\pm}0.2mm$ in diameter. The hatching of the embryo took place in about 60 hrs after fertilization under water temperature of $20{\pm}1^{\circ}C$ and the newly hatched larvae were average $6.4{\pm}0.4mm$ in total length. At 10 days after hatching, they were average $11.7{\pm}0.2mm$ in total length and their yolk sac were completely absorbed. At 46 days after hatching, they became to juvenile stage and reached $19.6{\pm}2.7mm$ in total length and all their fin rays were formed. At 125 days after hatching, the juvenile were $54.9{\pm}15.8mm$ in total length and their body shape were similar to the adult fish. At 236 days after hatching, they fish were $54.9{\pm}15.8mm$ in total length and their body color were similar to the adult fish.

• Korean Journal of Ichthyology
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• v.28 no.3
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• pp.156-163
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• 2016

Egg development and early life history of Korean southern spine loach, Iksookimia hugowolfeldi, were observed in the present study. Eggs were obtained after injecting females with 0.5 mL/kg of Ovarprim. Eggs were artificially fertilized using the dry method in the laboratory. Number of spawned eggs were $1,933{\pm}530per$ individual. Mature eggs were slightly adhesive with light yellowish coloring, and they measured $1.35{\pm}0.03mm$ in diameter. Hatching of the embryo occurred 56 h (50%) after fertilization at water temperature $25^{\circ}C$, and newly hatched larvae were averaged of $5.6{\pm}0.18mm$ in total length. At 5 days after hatching, larvae averaged $7.8{\pm}0.31mm$ in total length and their yolk sacs had been completely absorbed. Beginning at 15 days after hatching, the fish entered the juvenile stage and reached $13.2{\pm}0.87mm$ in total length. At 100 days after hatching, the band patterns and external form of juvenile were similar to those of adults, and they averaged $49.2{\pm}4.29mm$ in total length.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.323-328
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• 1982

Kareius bicoloratus (Basilewsky) is one of the commonly found right-eye flounders and widely distributed in the coastal waters of Korea and Japan. On December 11,1980, the ailthors carried out an experiment to obtain a large number of fertilized eggs from wild adult fish caught by a trawler. The fish were obtained from Maisaka fish market, Shizuoka Prefecture, Japan. The egg is pelagic, spherical in shape and measuring 1.014-1.04 mm in diameter. The yolk as well as the egg capsule is colorless and transparent, and contain no oil globules. The hatching took place in 73 hr 45 min after fertilization at the water temperature $8.0-9.5^{\circ}C$. Newly hatched larvae are 3.09-3.146 mm in total length, with the anus situated in the middle of the body. The marginal fin does not have Pigment cells and myotome number is 17+20=37. Within one day after hatching, the larvae attained 3.77 mm in total length, and there appeared three or four melanophore on yolk sac. When the larvae attained 3.96 mm in total length, melanophores began to appear on the eye ball. Two days after hatching, the larvae attained 4.05 mm in total length, most of yolk material was absorbed, and the caudal fin began to grow at the terminal part of the notochord. When the larvae attained 4.21 mm in total length, mouth and eyes began to move. After 3 days, the larvae attained 4.342-4.394 mm in total length, alimentary canal differentiated, melanophores appeared on the lower jaw and posterior part of the fin membrane. When the larvae attaind 4.576 mm in total length, marginal line of dorsal fin membrane became concave.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.93-101
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• 2012

In the present study, egg development and early life history of Korean spined loach, $Iksookimia$ $koreensis$, were observed. Adult fish were sampled using spoon nets in Okgye-ri, Hoengseong-gun, Gangwon-do, Korea in July 2010. Eggs were obtained after injecting females with Ovarprim. Eggs were then artificially fertilized in the laboratory using the dry method. Mature eggs were slightly adhesive and transparent with a light yellowish color, and measured $1.40{\pm}0.04mm$ (mean${\pm}$SD) in diameter. Hatching of the embryo occurred approximately 50 h after fertilization in the water at $23^{\circ}C$, and newly hatched larvae were averaged $4.7{\pm}0.21mm$ in total length. 5 days after hatching, the averaged total length of larvae was $7.1{\pm}0.25mm$ and their yolk sacs had been completely absorbed. 17 days after hatching, fish started to enter the juvenile stage and reached $12.2{\pm}1.10mm$ in total length. 80 days after hatching, the band patterns and external form of juvenile fish were similar to those of adults, and they averaged $31.0{\pm}3.98mm$ in total length.

• Korean Journal of Ichthyology
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• v.24 no.1
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• pp.48-55
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• 2012

Egg development and early life history of the slender shinner, $Pseudopungtungia$ $tenuicorpa$ were investigated to provide basic information regarding biological characteristics and restoration in 2010. Eggs were obtained by injecting females with Ovaprim and then fertilized using the dry method in the laboratory. Matured eggs were strongly adhesive, opaque and grayish and measured $1.96{\pm}0.08mm$(mean${\pm}$SD) in diameter. Fertilized eggs hatched 240 h after fertilization at $23^{\circ}C$, and newly hatched larvae an average $8.6{\pm}0.25mm$ in total length. At 2 days after hatching, larvae averaged $9.0{\pm}0.37mm$ in total length and their yolk sacs had been completely absorbed. About at 10 days after hatching, they beacme to juvenile stage and reached $10.6{\pm}0.44mm$ in total length. At 70 days after hatching, the band patterns and external form of juveniles were similar to those of adults, and they averaged $36.0{\pm}2.13mm$ in total length.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.52-61
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• 2017

The egg development and early life history of Korean endemic fish, Squalidus multimaculatus (Gobioninae), were investigated. The eggs from the females were obtained by injecting 10 IU/g of human chorionic gonadotropin and inseminated by wet method in the laboratory. The fertilized eggs were 0.8~0.9 mm in diameter and had no oil globules. The embryo began to hatch about 65 hrs after fertilization under water temperature of $24{\pm}1^{\circ}C$. The newly-hatched larvae were 2.5~3.1 mm in total length, and their mouth and anus were not opened. Four days after hatching, the postlarva were 4.0~4.2 mm in total length, and their york sacs were completely absorbed. They entered the juvenile stage when all fin-rays were formed at 30 days after hatching, and their total length were 11.2~15.7 mm. At 45 days after hatching, the external from of juveniles were similar to those of adults (total length were 18.8~22.5 mm), and 80 days after hatching, the external characteristics from of juveniles were same to adults (total length were 25.7~35.9 mm).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.317-331
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• 1989

Chaenogobius laevis inhabit brackish waters. Adult male protects egg mass laid under the stones. The egg with small oil globule varied from 3.40 to 4.04 mm in diameter. When water temperature is $22.0\~23.0^{\circ}C$, larvae hatched about 113 hours after fertilization. The newly hatched larvae reared for 33 days grow up to 12.10 mm in total length and developed to the jevenile. When larvae length attained about 8.0 mm, jaw bones were more rapidly ossified than vertebrae and cranium.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.65-73
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• 2013

Egg development and early life history of the Korean spine loach, Iksookimia pumila was investigated to provide basic information regarding biological characteristics and restoration. Adult fish were sampled using spoon net in the Baek Stream, Sangseo-myeon, Buan-gun, Jeollabuk-do, Korea, 7 July 2010. Eggs and sperms were obtained from the females and male with Ovaprim injecting (0.5 mL/kg) and then fertilized using the dry method in the laboratory. Number of spawned eggs were 1,107 (352~1,440). Spawned eggs were slightly adhesive, light yellowish coloring and measured $1.3{\pm}0.04$ mm (mean${\pm}$SD) in diameter. Spawned eggs hatched out 52 (47~55) hours after fertilization at water temperature of $23^{\circ}C$, and newly hatched larvae an average were $4.7{\pm}0.14$ mm in total length. At 5 days after hatching, larvae averaged $7.1{\pm}0.20$ mm in total length and their yolk sacs had been completely absorbed. Beginning at 17 days after hatching, fish entered the juvenile stage and reached $11.0{\pm}0.50$ mm in total length. At 100 days after hatching, the band patterns and external form of juvenile fish were similar to those of adults, and they averaged $31.3{\pm}3.98$ mm in total length.

• Journal of Aquaculture
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• v.10 no.1
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• pp.25-32
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• 1997

Develoment precess and characteristics of eggs of the geoduck clam, Panope japonica are reporting in this study. Eggs and sperm were excised from gonad, artificially fertilized in an aquarium, reared under various temperature regimes, and record and record the larval period and the time need to reach a certain larval stage from ferilization. Unfertilized eggs of P. japonica appeared to be oval with a mean diameter of $70\mu$m and they became spherical after fertilization. The eggs of P. japonica can be classified as demersal. At a constant water temperature of $ 11^{citc}C$, it took 4 hours form fertilization to become four-cell stage, two days to become trochophore larvae, three days to become D-shape larvae, twenty-three days to become umbo stage, and thirty-six days to become fully grown veliger ready form settlement. A negative correlation was observed between the water temperature and the larval period of P. japonica. From fertilization to D-shape larvae, it took five days at 8$^{\circ}C$, while it was only two days to become D-shape larvae at $ 17^{citc}C$. Time required to D-shape larvae from fertilization was proportional to temperature, and the relationships were expressed as follows : To 8-cell stage, 1/t=0.0209 w-0.1167 (r=0.9967) To blastula stage, 1/t=0, 0055 w-0.0192 (r=0.9825) To trochophore stage, 1/t=0.0034 w-0.0155 (r=0.9907) To D-shape larvae stage, 1/t=0.0014 w-0.0023 (r=0.9843) (t, time in hours ; w, water temperature) Bioligical minimum temperature for egg development was calculated as 3.82$^{\circ}C$ in average.

• Korean journal of applied entomology
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• v.24 no.3 s.64
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• pp.141-149
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• 1985

Embryonic developmental rates of the Oriental tobacco budworm, Heliothis assulta Guenee, were compared at various constant temperatures and 16 hours of light, and detailed embryogenesis was also studied at $25^{\circ}C$. The egg was nearly globular in form and had an average equatorial diameter of 0.53mm. A single micropyle was in the center of the circular area at the anterior pole of the egg. Durations of embryogenesis at 20, 25, 30, and $35^{\circ}C$ were 147, 81, 61, and 67hrs, respectively. Embryonic death was especially higher at $35^{\circ}C$ than any other temperatures investigated. Embryogenesis progressed with changes in color and pattern, which are quite characteristic at each developmental stage of the embryo. At $25^{\circ}C$, organogenesis began in 14hrs after oviposition, formation of gut completed in 44hrs and eclosion occurred in 80hrs. The embryo formed along the long axis at early developmental stage, moved towards the equatorial plane in 24hrs, and made a half-turn on the plane in 36hrs. In 40hrs, head was oriented to the anterior pole of the egg until eclosion.