• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.198-205
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• 2011

Early life history of the endangered species, Gobiobotia macrocephala was investigated to provide baseline data for biological characteristics and recovery. Adult fish were sampled by spoon net at Hongcheon-gun, Gangwon-do, Korea in April to June 2010. The female's eggs were obtained by injecting Ovaprim and fertilized by dry method in the laboratory. The mature eggs were slightly adhesive and transparent with greyish and average 0.89${\pm}$0.04mm in diameter. The hatching of the embryo took place in about 107 hours after fertilization under water temperature of 23$^{\circ}C$ and newly hatched larvae were average 4.6${\pm}$0.16mm in total length. At 4 days after hatching, they were average 6.1${\pm}$0.20mm in total length and their yolk sacs were completely absorbed. From 15 days after hatching, they entered the juvenile stage and reached at 8.6${\pm}$0.67mm in total length. At the 100 days after hatching, their band patterns and external form were similar to those of adults, and they averaged 31.5${\pm}$3.32mm in total length.

• Korean Journal of Ichthyology
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• v.10 no.2
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• pp.184-190
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• 1998

The early life history of black bullhead, Pseudobagrus koreanus, endemic to Korea was investigated to get biological information needed in artificial production of seedlings and in recovering natural resources. The fertilized eggs showed some characteristics in having heavy sticky material and minute folds which is formed radical pattern on the egg membrane. The shape of egg was spherical and $2.59{\pm}0.08$(2.45~2.70, n=10)mm in diameter. The yolk had not oil globule. The first cleavage was observed 2 hrs after insemination at $21{\sim}23^{\circ}C$, and the progressive cleavage were done about 30 min. interval. The characteristic changing of the yolk surface started at morula stage and continued to the end of gastrula. Hatching was started 72 hrs and completed 90 hrs after fertilization. The size of the larvae were 5.41~5.81mm in total length and 2.76~2.94mm in preanal length, and the number of so mites was 15-16+33~34(48~50). The barbels and swimbladder were completed and all the fins except second dorsal were appeared 1 week after hatching. The larvae attained 9.67~10.52mm in total length and 5.20~5.65mm in preanal length. All the fin sets and color pattern were completed 2 weeks after hatching and body mucus was secreted at that stage. The juvenile attained 14.59~16.02mm in standard length, 3.31~4.16mm in head length and 8.07~9.31mm in prenal length.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.241-265
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• 1989

The purpose of present study is to describe the taxonomy and early life history of Korean pomfrets, genus Pampus. Egg diameter varied from $0.83\~1.27mm\;and\;1.05\~1.41mm$ in P. argenteus and P. echinogaster respectively. Larvae of P. echinogaster of 16.5 mm in total length has full number of fin rays and enter the juvenile period. The egg is matured at 185.0 mm in total length in P. argenteus and at 95.5 mm in total length in P. echinogaster. P. echinogaster is ossified from jaw bone at $8.5\~10.0mm$ in to1 length and followed by ossification of vertebrae and visceral skeleton. P. argenteus and P. echinogaster are distinguished by the morphology of jaw, fin and isthmus. In P. argenteus, wavy ridges extends over the upper part of pectoral fin and gill membrane is broadly united to isthmus, while in P. echinogaster the ridges are limited to the base of pectoral fin and gill membrane reaching isthmus. These Pampus spp. are easily distinguished based on internal features, such as number of vertebrae, gill raker, pyloric caeca, epipleural bone, esophageal sat and length of intestine.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.282-294
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• 2000

The reproductive ecology and the early life history of Macropodus chinensis were investigated in aquarium. Mature male made the bubble nest and spawned with wrapping the female and reverse posture. The parental male protected the offspring until the larvae depart the bubble nest. Egg productivity and egg hatching rate were the highest at water temperature in $28^{\circ}C$ and $26^{\circ}C$ respectivity than any other artificial temperature. The eggs were buoyant, globular and 0.95${\sim}$1.05 mm in diameter. Cleavage was progressed at intervals of 15 minutes. Eggs hatched in 42${\sim}$44hours after fertilization and the newly hatched larvae were 3.0${\sim}$3.2 mm in total length. The lawae were 4.5${\sim}$5.4 mm in 4${\sim}$5 days after hatching and fed on the food with dispersion from the nest. In 40${\sim}$45 days after hatching, all fin rays completely developed, and juveniles reached 18.2${\sim}$23.5 mm in total length. In 90${\sim}$110 days after hatching, body from of young fishes were similar to adult with 37.4${\sim}$48.2 mm and represented secondary sexual characters longer than 45.0 mm in total length, and about 120 days, fishes began spawning(water temperature for ontogenesis: $26.0{\pm} 1^{\circ}C$).

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.136-143
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• 2011

Early life history of the endangered species Gobiobotia brevibarba was investigated to provide baseline data for biological characteristics and restoration. Adult fish were sampled by spoon net capture at Hongcheon-gun, Gangwon-do, Korea, in April 2010. Eggs were obtained after injection of Ovarprim and were artificially fertilized by the dry method in the laboratory. The mature eggs were slightly adhesive and transparent with greyish and average $1.24{\pm}0.07$ mm in diameter. The hatching of the embryos took place about 120 h after fertilization at a water temperature of $23^{\circ}C$. The newly-hatched larva averaged $5.5{\pm}0.29$ mm in total length. Four days after hatching, they averaged $7.4{\pm}0.26$ mm in total length and their yolk sacs were completely absorbed. From 15 days after hatching, they entered the juvenile stage and reached $9.9{\pm}0.72$ mm in total length. One hundred days after hatching, their band patterns and external form were similar to those of adults, and they averaged $36.0{\pm}3.11$ mm in total length.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.107-117
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• 1998

The cultivation for development of Ascaris suum from the second-stage larvae($L_2$) embryonated egg and the third-stage of rat-derived larvae($L_3$) recovered from lung of rats were performed to use the screening test of anthelmintics in vitro. The preparations of larvae for cultivation were that the artificially-hatched $L_2$ incubated the embryonated eggs of Ascaris suum in 0.1% formalin solution at $25^{\circ}C$ for 28 days and the rat-derived larvae($L_3$) recovered from the lung of rat infected with the embryonated eggs of Ascaris suum on 7 days after infection(DAI). The cultivation for development of Ascaris suum from the embryonated eggs($L_2$) and the rat-derived larvae($L_3$) for 14 days in RPMI medium 1640(with 5% bovine calf serum) were as follows : 1. The sizes of the liberated larvae($L_2$) which were artificially hatched from embryonated eggs with glass beads(diameter 5mm) were $190{\sim}250{\mu}m$ on 1 days in culture(DIC). The second-stage larvae were molted into third-stage larvae(early $L_3$; $250{\sim}300{\mu}m$) and the features of these larvae were first observed such as cephalic cuticle, esophageal lumen and anus etc. on 5 DIC and the sizes of late third-stage larvae were $250{\sim}450{\mu}m$ on 10 DIC. The sizes of early fourth-stage larvae($L_4$) were $500{\sim}700{\mu}m$ and the features of these larvae were more pronounced in internal organs on 15 DIC. 2. The sizes of third-stage larvae($L_3$) recovered from the lung of rats were $1,340{\sim}1,370{\mu}m$ and the feartures of cephalic cuticle, esophageal lumen, intestine, rectum, anus were visualized by inverted microscope on 1 DIC. The fourth-stage larva($L_4$) completed by third ecdysis were recognizable and sizes of early fourth-stage larvae were developed as $1,400{\sim}2,200{\mu}m$ on 5 DIC. The sizes of middle fourth-stage of larva were $1,900{\sim}2,300{\mu}m$ and the thickened epithelial rectum was observed on 10 DIC. The rectum and anus of late fourth-stage larva($L_4$ $2,500{\sim}3,200{\mu}m$) had developed completely in RPMI medium 1640 on 15 DIC.

• 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 Ichthyology
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• v.28 no.4
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• pp.260-266
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• 2016

We determined the morphologic characteristics (body weight and abdomen inflation degree) of the mother fish of sevenband grouper, Epinephelus septemfasciatus producing the healthy eggs. Experimental fish were chosen from the reared fish in the sea cage for 6 years. The fish were divided into four size groups by body weight: 4.0~5.0, 5.0~6.0, and 6.0~7.0 kg and four stages (I~IV) by the abdomen inflation degree. After hormone treatment, we observed the ovulation amount of induced eggs, rate of buoyant, fertilization, embryonic survival, and hatching. Egg and oil globule diameter was measured. In order to observe gonadal development, we calculated gonadosomatic index (GSI) and conducted its historical analysis. The ovulation occurred from all experimental fishes over 5.0 kg. The rate of buoyant, fertilization, and embryonic survival was the highest in 6.0~7.0 kg. Hatching rate was the highest in 5.0~6.0 kg. Stage I and II did not induce ovulation. GSI was $0.31{\pm}0.10%$ in stage I, $0.74{\pm}0.25%$ in stage II, $4.68{\pm}0.40%$ in stage III and $6.86{\pm}0.12%$ in stage IV. The rate of buoyant, fertilization, embryonic survival and hatching was the highest in stage III.

• Development and Reproduction
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• v.12 no.3
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• pp.283-288
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• 2008

The Pseudogobio esocinus were caught at Wyuleo-ri, Gyeombaek-myeon, Boseong-gun, Jeollanamdo from April to May 2003. The fishes were incubated in transparent aquarium located at the laboratory of Chonnam National University, and their embryonic and larval development were observed. The fertilized eggs were spherical, semitransparent, and adhesive, and were $1.98{\pm}0.19mm$ (n=50) in diameter. The embryo, including 31$\sim$32 myotomes, hatched through egg membrane at 164 hrs after fertilization. The newly-hatched larvae were $4.61{\pm}0.83mm$ (n=10) in total length (TL). At that moment, yolk was not absorbed, and mouth and anus were not open. Star and spot shaped melanophores were distributed on the lens, and dorsal, ventral, and caudal parts. At 42 days after hatching, larva was $16.22{\pm}0.65mm$ (n=10) in TL. Melanophores were scaterred at head, back, and side parts. Morphological features of the embryo were transferred to juvenile stage showing similar features with those of the adult fish.

• Korean Journal of Animal Reproduction
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• v.9 no.2
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• pp.124-132
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• 1985

The work was conducted to clarify the development of testes and histological changes of the Seminiferous tubules that is the Surface area, diameter, length of the tubules and the process of Spermatic cells growth in Seminal epithelium in relation to Sexual maturity of the meat-type cockerels. In addition the present experiments were planned to gain some basic data helpful for the study of reproductive physiology in meat-type cockerels and also to compare the histological changes Seminiferous tubules between egg and general purpose type cockerels. 1. The growth pattern of body weight, testes and comb was classified into four phase according to age. Body weight increased up to about 2kg at 2nd stage and to 4.3kg at 4th stage while at 3rd stage the growth rate of body weight was slower. The tests developed slowly until 22 weeks of age with no correlation to the growth of body weight. However, it grew rapidly afterwards, reaching 27.79$\pm$9.26gm and 42.46$\pm$5.33 gm at 24 and 28 weeks of age, respectively. The spermatozoa was seen first at 24 weeks of age. On the other hand, comb grew at similar rate to the testes, weighing on the average 21.78$\pm$6.48gm and 41.42$\pm$1.25gm at 24 and 28 weeks of age, respectively. 2. The areal rate of the Seminiferous tubules to interstitial tissues was 66%:34% at 2 weeks of age and the rate of the former increased in comparison to that of the latter as they grew older, becoming 94%:7% between at 24 weeks of age, when the testes weight increased rapidly too. 3. Diameter of Seminiferous tubules at 2 weeks of age was 42.76$\pm$1.04$\mu$m and then it gradually increased as the testes grew until 22 weeks of age, when it grew rapidly, increasing about 2.9 times of those of 2 weeks and at last increased up to 5 times at 24 weeks. 4. Length of Seminiferous tubules was 4.5cm at 2 weeks and then it was gradually increased. At 22 weeks old the length of tubules was icnreased rapidly being 321 meter and increased more than double, being 658 meter at 24 weeks old. 5. The cells of Seminal epithelium developed poorly and the number of cells were relatively few until 16 weeks old. Afterwards the cells increased rapidly in number and at 18 weeks, the number became twice of those of 16 weeks, reaching 140.43$\pm$43.6. At 24 weeks the cells increased more rapidly, reaching to 10 layers and Spermatozoa were first time seen.