• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.262-272
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• 2021

The egg development and early life history of Tribolodon hakonensis that collected from the Seomjin River were studied. The fertilized eggs of the T. hakonensis were slightly adhesive and separated with a yellow yolk and no oil globule. The size of the eggs was an average of 2.89 mm (2.79~2.96) in diameter. Fifty percents of the embryos were hatched in about 63 hrs after fertilization at water temperature of 20℃. The newly hatched larvae showed average 6.92 mm (6.09~7.60) in total length. At 8 days after hatching, they were 13.75±0.67 mm (n=10) in total length and their yolk sacs were completely absorbed, opening mouth and anus (postflexion larvae stage). At 40 days after hatching, they became juvenile and reached 26.99±1.82 mm (n=10) in total length and all their fin rays were formed. At 137 days after hatching, the young fish were 72.63±10.7 mm (n=10) in total length and their body shape, color and behavior were similar to those of adult fish. The size of eggs and the larva after hatching significantly affected the initial growth among groups of genus Tribolodon, and the hatching time of fertilized eggs and the growth rate of the early life history according to the water temperate were different.

• Fisheries and Aquatic Sciences
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• v.4 no.1
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• pp.39-46
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• 2001

To examine the effect of copy number-dependent transgenic genotype on the expression of foreign gene, stable hemizygous and homozygous transgenic breeding line was established using artificial parthenogenesis. For this purpose, induced diploid gynogenetic transgenesis was optimized in mud loach (Misgurnus mizolepis) using UV-irradiated cyprinid loach (M. anguillicaudatus) sperm and thermal shocks. Optimum UV range for inactivation of cyprinid loach sperm was between 3,150 to $4,050\;ergs/mm^2$ The UV-irradiated sperm were inseminated into eggs from recessive color strain (yellow) or heterozygous transgenic mud loach containing CAT gene. Cold shock at $2^{\circ}C$ for 60 min, 5 min post fertilization successfully restored the diploidy of eggs inseminated with UV-irradiated sperm. Restoration to diploidy was confirmed by flow cytometry and gynogenetic status was verified by examining maternal exclusive inheritance of multi-locus DNA fingerprints, body color and transgenic marker. Putative isogenic transgenic fish clearly showed homozygous status at trans gene locus based on Southern blot hybridization and progeny testing. Further, such homozygous gynogenetic diploids revealed the increased levels of transgene expression, when compared to those of heterozygous (hemizygous) transgenic fish.

• Development and Reproduction
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• v.18 no.4
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• pp.241-249
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• 2014

Hyphessobrycon eques is a famous fish for ornamental fish market and aquarium. They are inhabit in regions of Amazon and Paraguay River basin. Serpae fishs were investigated 2-3 males are chased to female, and then males attempted to simulate the females abdomen. After fertilization, eggs were kept in incubators at $28^{\circ}C$. The fertilized eggs had adhesive and demesal characteristics and had a mean diameter of $0.92{\pm}0.01mm$. Larvae hatched at 16 hrs post fertilization. The hatched larvae averaged $2.90{\pm}0.16mm$ in total length ($L_T$). Complete yolk sac resorption and mouth opening occurred on the third day post hatching. At 45 days post hatching, the larvae were $12.5{\pm}1.60mm$ $L_T$ and had reached the juvenile stage.

• Applied Microscopy
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• v.44 no.3
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• pp.96-99
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• 2014

Study on the egg envelope of an endemic Korean freshwater fish, Coreoleuciscus splendidus was carried out by light and scanning electron microscopes during its spawning season. The egg envelope on the entire egg is filled with plenty of long cylinder-like villi before and after fertilization. The fertilized eggs consist of two regions, the attaching and non-attaching parts to stick to the substrates. The villi covering the fertilized eggs have three kinds of villi in its length: 1) normal- sized villi of an average of $10.6{\mu}m$ on the non-attachment part; 2) longer and more slender villi over about $20{\mu}m$ on the attachment part, at least being two times longer than those of the non-attachment; and 3) shorter villi under about $5.0{\mu}m$ around the micropyle, with half the size of the non-attachment villi. The micropyle rotated in a counter-clockwise direction with five pieces of the ridges.

• Korean Journal of Ichthyology
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• v.26 no.1
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• pp.42-49
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• 2014

A total of 4 pelagic eggs and 24 larval fish species were collected in Masan Bay. Engraulis japonicus eggs predominated in pelagic eggs. Abundant larval fishes were Omobranchus elegans, Scomber japonicus, Acanthogobius flavimanus, Hexagrammos otakii, Repomucenus sp., Scartella cristata and Gobiidae sp., and these 7 species accounted for 78.5% in the total number of individuals. Temporal and spatial variation in both species composition and abundance of was large: the peak abundances of pelagic eggs and larval fishes occurred in July 2007, whilst these were lowest in February 2007. Higher abundance of ichtyoplankton were at station 5 than those of other stations. Temporal changes in the abundances of pelagic eggs and larval fishes corresponded with temperature. Pelagic eggs and larval fishes varied among stations between with shallower inner stations and deeper outer stations with physical characteristics such as depth and local topography.

• Journal of Aquaculture
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• v.12 no.3
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• pp.197-204
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• 1999

Successful produciton of seedlings for marine fish species are highly influenced by the aquisiton of sufficient number of good-quality eggs on required time. human chorionic gonadotropin has been used to induce successful ovulation for the purpose. Rabbitfish, siganus canaliculatus, is inhabited along the coast of Cheju Province and treated valuably for raw fish and fish roasted with seasoning. Female wild-captured rabbitfish (314 to 279 g in body weigth) were injected into intraperitoneal space with human chorionic gonadotropin (HCG) of 5,00,1,000, and 1,500 IU/kg body weight during spawning season of July 14 (trial 1), and July 27 (trial 2). Test fish in trial 1 were injected two times, first on July 14 and second on July 21 with one weekinterval because of no ovulation symptoms, but just one time in trial 2. All females injected both 1,000 and 1,500 IU/kg body weight ovulated in all trials. Among 500 IU/kg injection treatments, just one female ovulated in trial 1 showing 25% of ovulation rate, but none ovulated in trial 2. Ovulation was not occurred in control goups during test period. Time to reach ovulation after injection was 172 to 270 hours in trial 1 and 77 to 132 hours in trial 2, showing shorter as spawning season approached. Generally, ovulation of smaller females were late than that of larger ones. Gonadosomatic index (GSI) and pseudo-gonadosomatic index (Pseudo-GSI) were ranged 22 to 33% and 19 to 28%, respectively. One female spawned 406,200 to 1,032,000 eggs, and obtainable eggs per 100g of body weight were calculated by 130,000 to 190,000. Spawning rates were comparatively high by 96.0 to 98.4%. Rates to reach embryo-formation and hatching were higher in 500 high by 96.0 to 98.4%. Rates to reach embryo-formation and hatching were higher in 500 and 1,000 IU/kg treatments than in 1,500 IU/kg treatment. The result of present study demontrates that HCG treatment during spawning season could become very useful for ovulation of rabbitfish and the suitable dosage was suggested as 1,000 IU/kg of body weight.

• Food Science of Animal Resources
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• v.26 no.4
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• pp.517-524
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• 2006

We investigated the effect of different kinds of dietary fats on the fatty acid composition, cholesterol content and quality of hens' eggs. The Haugh units, breaking strength, shell thickness and yolk color were not significantly different among the test groups. The type of dietary fat fed each test group notably altered the polyunsaturated fatty acid composition and cholesterol content of egg yolk. The n-6 fatty acid content of egg yolk was highest in the corn oil fed group being 31.61%, and this tended to decrease in the tallow, linseed oil and fish oil fed groups(P<0.05) in that order. The n-3 fatty acid content of egg yolk tended to increase in the linseed oil and fish oil fed groups with values of 9.74% and 5.16%, respectively(p<0.05). The increase of n-3 fatty acids in the yolk resulted in a reduced cholesterol content of the eggs. The cholesterol content ranged from $15.98{\sim}18.37mg/g$ of yolk or $227{\sim}261mg/60g$ of egg(p<0.05). The cholesterol content of egg yolk was highest in the tallow fed group, and significantly reduced to 13.01% in the fish oil group, 11.49% in the linseed oil group and 6.91% in the corn oil group(p<0.05). This result suggests that it is possible to reduce the cholesterol content or to increase the n-6 and n-3 polyunsaturated fatty acid contents in eggs by the manipulation of dietary fats.

• Korean Journal of Ichthyology
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• v.29 no.3
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• pp.190-196
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• 2017

The egg and larval development of pale chub, Zacco platypus were determined by observation of laboratory reared larvae from hatching. The experimental adult fish were collected in Wicheon of Nakdong river in June 2016, The eggs and larvae were reared in the experimental tanks, and observed their morphological change. The egg diameter ranged from 1.68 to 1.78 mm ($mean{\pm}SD$, $1.73{\pm}0.07mm$, n =30). The eggs were hatch 70 hours after fertilization. The total length (TL) of the newly hatched larvae ranged from 5.39 to 5.42 mm ($5.40{\pm}0.02mm$, n=10). On the 8 days after hatching, 10 fin rays were formed in caudal fin at 7.89~7.93 mm TL ($7.91{\pm}0.02mm$, n=10). On the 44 days after hatching, the juveniles ranged from 16.1~16.5 mm TL ($16.3{\pm}0.28mm$, n=10).

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.478-484
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• 2004

On 11 June 1991, eggs from the brood stock of small yellow croaker (Larimichthys polyactis) were artificially fertilized using the standard dry method and were hatched. Each of the fertilized eggs (1.1-1.2 mm in diameter) had an oil globule and was transparent and buoyant. The fertilized eggs hatched in a range of water temperatures $(17.5-20.3^{\circ}C)$ 44 hrs after fertilization. The total lengths of the newly hatched larvae were 3.1-3.3 mm, and these hatchlings had 31 myotomes (10+21). Melanophores and yellow-brown chromatophores were concentrated on the head, at the ventral part of the yolk, and in the middle of the tail. Four days after hatching, the larvae completely absorbed the yolk and became flexions of 5.1-5.5 mm in total length. Fifteen days after hatching, one spine (the anterior tip of the maxillary) appeared in the upper jaw and three spines developed at the upper parts of the eyes and on the posterior part of the head. At this stage, the larvae were approximately 8.3 mm long. Thirty-nine days after hatching, juveniles (1.9-3.4 mm in total length) had a pointed tail fin. By 66 days after hatching, the juvenile fish (about 4.0-6.5 mm in total length) were similar to adult fish in body shape. The larvae of L. polyactis could be distinguished from those of L. croacea by two distinct characteristics: the large number of vertebrae (28-29), and a relatively small bony ridge on the occipital region of the head.