• The Korean Journal of Ecology
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• v.1 no.2
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• pp.44-48
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• 1977

The spawning behavior and developmental pattern of the Korean eleotrid fish (Odontobutis obscurus) was investigated in one of the tributary of Han River. The spawining of this species begins on April and continues up to August, whereas, the spawning. of same species were between the end of June and the middle of July in Kyushu, Japan. August The spawning places were the margin of river, its the bottom composed of sand and pebble (Table 5). The velocity of water in the spawning places was 0-40cm/sec, and the depth of waters was 10-40cm. The egg was spawned on underside of stone in the spawning places with one or two folds and ellipsoid in shape, 3.4mm in long diameter and 2.0mm in short diameter. The yolk is 1.2mm in diameter and yellow in color. For hatching of the egg, it takes one month in, $16^{circ}C~19^{\circ}C$ water, in Japan, whereas it takes only 14 days in $20^{circ}C~30^{\circ}C$ wate rin the study area. The growth rate of larva and juvenile fish were as follows: new hatched larva is 45mm in length; after 5 days it became 5.0 to 5.5mm in length and 1.2 to 1.5mm in height after 20 days. it became 11.0mm in length and 2.3mm in length. The mean size of the mature female is 110mm in total length and larger 10mm than that of the same fish found in Japan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.408-417
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• 2019

This study was conducted to identify taxonomic differences in the characteristics of Rhodeus uyekii and Rhodeus ocellatus during their initial life history via an interspecific hybridization experiment. Hybrids were compared to their parent species, and the findings were used to inform developmental research in commercially useful aquarium fish. The hatching rates of the cross-bred eggs were 75.9% for cross UO (R. uyekii ♀${\times}$R. ocellatus♂) and 71.9% for cross OU (R. ocellatus♀${\times}$R. uyekii♂), which did not differ greatly from the hatching rates of the normal cross-bred group. Backcross experiments resulted in 100% egg mortality during development. Newly hatched larvae of the original hybrid crosses were similar to those of the maternal line, and the color of the egg yolk was similar to that of the paternal line; therefore, the respective traits of the interspecific parents were identifiable within the cross-bred offspring.

• Animal cells and systems
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• v.14 no.1
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• pp.25-30
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• 2010

We employed a new and improved differential display reverse transcription-polymerase chain reaction (DDRT-PCR) method, which involves annealing control primers (ACPs), to identify the genes that are specifically or prominently expressed in olive flounder (Paralichthys olivaceus) juveniles (35 days post-hatch; dph) compared to larval-stage (dph 21) flounder. Using 60 ACPs, we identified eight differentially expressed genes (DEGs) and basic local alignment search tool (BLAST) searches revealed eight known genes. Gene expression levels were confirmed by RT-PCR. Phosphoglucose isomerase (PGI) was highly expressed at 21 dph, while nephrosin, myosin light chain (MLC), myosin heavy chain (MHC), carboxypeptidase A, chymotrypsin B, fish-egg protein, and matrix protein were expressed at 35 dph. PGI, MLC, and MHC expression was further analyzed by RT-PCR. The differentially expressed genes identified in this study may provide insights into the molecular basis of development in olive flounder.

• Development and Reproduction
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• v.18 no.1
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• pp.13-23
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• 2014

This study is conducted to monitor the morphological developmental features of the egg development, larvae and juvenile of Epinephelus septemfasciatus, the fertilized eggs were gotton using artificial insemination. Matured parents are collected from marine caged fish farms in Geomun-ri, Samsan-myeon, Yeosu-si, Jeollanamdo Korea in June 2012. The fertilized eggs were pelagic eggs containing one oil globule, and measured 0.81~0.89 mm ($0.85{\pm}0.04mm$, n=50) in diameter. In regard to rearing environment, the water temperature is $21.0{\sim}23.0^{\circ}C$ and the salinity is 32.0~33.2‰. Hatching was observed from 48 hours after fertilization, the mouth and anus of prelarvae was not opened but had egg yolk at newly hatched. 4 days after hatching, the mouth and anus of postlarvae was opened and began to eat Rotifer and was measured 2.40~2.49 mm ($2.45{\pm}0.03mm$ n=10) in total length. 12 days after hatching, postlarvae was measured 3.77~4.67 mm ($4.27{\pm}0.33mm$) in total length, its the second pole tide of dorsal fin and the first pole tide of pelvic fin was extended longitudinally. 71 days after hatching, juvenile was measured 40.5~45.4 mm ($42.6{\pm}2.04mm$) in total length. Seven bands were observed in body, and pole tides of dorsal and pelvic fins were shortened.

• Journal of Life Science
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• v.13 no.1
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• pp.34-41
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• 2003

The hatching of fertilized egg and early development of larval black seabream, Acanthopngrus schlegeli by immersion of 3,5,3'-triiodo-L-thyronine ($T_3$) with doses of 0.01~0.5 ppm in tank were examined for early development periods and compared with control fish immersed by 0.1 N NaOH and 99% alcohol. Larvae were fed with rotifers for first 5 days during experimental period. Yolk absorption of larvae from $T_3$ immersion groups were significantly faster than that of control. Although hatching times among each groups were not significant difference. the hatching rates of larvae in higher doses (0.1 ppm and 0.5 ppm $T_3$ groups) were significantly lower than control. The results of $T_3$ immersion experiments to newly hatching larvae indicated that exogenous $T_3$induced significant faster the absorption of yolk and oil globule, faster the development of myotome and digestive duct and higher the growth rate of larvae than larvae of control. These results indicate that $T_3$ immersion supplements appear to confer a distinct advantage to eggs and larvae of black seabream, which is in early fragile developmental stage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.134-138
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• 1999

Eggs and larval development of Chelon affinis were reared and observed in the laboratory with parent fishes obtained in the Minrak fish market Pusan on March, 1997. The spawned eggs of the species are transparent, round, separated, floated, and their diameters were varied within 0.95$\~$1.06 mm. Hatching began about 73 hours after spawning at $16.0^{\circ}C$. The newly hatched larvae were 1.72$\~$1.92 mm in total length with 19 myomeres, mouth and unopened anus, rod shape melanophores distributed in body. The larvae absorbed yolk material completely in 5 days after hatching and became postlarvae.

• 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 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.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.

• Korean Journal of Ichthyology
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• v.26 no.2
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• pp.112-117
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• 2014

The spawning behavior, development of eggs and larvae of the blennioid fish, Dictyosoma burgeri were investigated. The blennioid fish were caught at Hwayang-myeon, Yeosu-si, Jeollanam-do from December 2013. The egg was spherical, measuring from 1.31 to 1.47 mm in diameter. The incubation period of the egg extended from 744 hrs at the temperature varying between 14.5 and $16.5^{\circ}C$. The newly hatched larvae were 7.10~7.60 mm(mean $7.34{\pm}0.18mm$) in total length. Two days after hatching, prelarvae was measured 8.43~8.47 mm (mean $8.45{\pm}0.01mm$) in total length. They began to eat rotifer and transformed to postlarvae stage. Six days after hatching, postlarvae was measured 9.06~9.13 mm(mean $9.10{\pm}0.02mm$) in total length.