• Korean Journal of Animal Reproduction
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• v.18 no.3
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• pp.183-189
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• 1994

We examined early development in loach(Misgurnus mizolepis) embryos with parthenogenetic agents well-known in mammals. Female loach was superovulated with an intraperitoneal injection of 15 IU human chorionic gonadotrophin (hCG) per gram body weight. After 13 h of hCG injection, the oocytes were obtained from the abdomen. The oocytes were activated with 10% ethanol in tap water or fish Ringer's solution for 5, 10 and 15 minutes(eTW5, 10, 15 and eFRS5, 10, 15), respectively. The activation rates were 29% and 10% in eFRS10 and eFRS15, 5% and 6% in eTW10 and eTW15 by judging the cleaved blastomeres. Whereas, no parthenogenetic embryo was produced by tap water or fish Ringer's solution alone. The activation rate with the fish Ringer's solution was higher than that of tap water. No embryonic development was observed by calcium ionophore, A23187, at concentrations of 10, 20, 40 and 100$\mu$M when treated for 1, 2.5 and 5 minutes, respectively. The activation agents did not cause early development as in mammalian eggs. Therefore, the results suggest that fresh water fish may have a different egg activation pathway from that of mammals.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.247-252
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• 2009

The egg development and early life history of the Korean endangered fish Koreocobitis naktongensis (Cobitidae) were investigated. Eggs from the females were obtained by injecting 10 IU/g of human chorionic gonadotropin and inseminated with sperm by the dry method in the laboratory. The fertilized eggs were 1.0~1.2 mm in diameter and had no oil globules. The embryo began to hatch about 38 hrs after fertilization under water temperature of $20{\pm}1^{\circ}C$. The newly-hatched larvae were 2.6~2.8 mm in total length, and their mouth and anus were not yet opened. Seven days after hatching, the postlarvae were 4.5~5.2 mm in total length, and their yolk sacs were completely absorbed. They entered the juvenile stage when all fin-rays were formed at 50 days after hatching, and their total lengths were 21~27 mm.

• 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 Ecology and Environment
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• v.41 no.1
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• pp.104-110
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• 2008

The egg development and early life history of Korean endangered natural monument fish, Iksookimia choii, were investigated in 2006. The eggs from the females were obtained by injecting 10 IU $g^{-1}$ of human chorionic gonadotropin and inseminated by wet method in the laboratory. The fertilized eggs were $1.1\sim1.3mm$ in diameter and had no oil globules. Hatching of the embryo began about 24 hrs after fertilization under water temperature of $25^{\circ}C$. The newly-hatched larvae were $2.5\sim2.7mm$ in total length (TL), and their mouth and anus were not yet opened. Six days after hatching, the postlarvae were $4.7\sim5.4mm$ TL, and tip of the caudal notochord was flexed $45^{\circ}$ upward. The juveniles stage was reached when all fin-rays were formed at 35 days after hatching, and their total length were $20\sim22mm$.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.6
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• pp.1209-1216
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• 2014

This feeding experiment was conducted to investigate the effects of slurry type diet on growth performance and survival rate of growing leptocephalus, eel larva. We need to find new materials of diets for rearing eel larvae. Test diets were formulated with the eggs of the shark, fish soluble concentrate, soybean peptide and fish protein hydrolysate. Fish (average length 6 mm) were fed 3 slurry type diet(A, B and C) based on shark egg for 5 times per day. During feeding experiment, survival rates were significantly different among 3 slurry type diets. Total protein, lipid, moisture, ash and free amino acids contents were analyzed for slurry type diets. Leptocephalus fed the C slurry type diet was grown up to $38.0{\pm}9mm$ at 150 days. But all leptocephalus fed B slurry type diet were died at 100 days, reaching $16.4{\pm}8mm$. This results suggest that basic information for diet development of eel leptocephalus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.419-421
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• 2001

Heritability estimations of masu salmon smelt at underyearing of age were described. Masu salmon was taken from aquaculture station of Mori in Japan. After fertilization, the offsprings in each family were reared in separate egg trays and fingerling tanks. The percentage of fish in each tank which smoltified at 11-month old was recorded, and environmental and genetic factors influencing the percentage smoltification were also studied. Percentage of smoltification was not significantly affected by the number of fish held in a tank, or fish density (correlation coefficient 0.10). However, there was a high correlation ($0.821\~0.565$) between smelt percentage and growth related traits of fish in a family. Heritability estimated from total data was $0.47\pm0.13$, when effects of tanks were ignored.

• The Korean Journal of Malacology
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• v.2 no.1
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• pp.26-29
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• 1986

Corbicula fluminea, one of the 2 species in the family Corbiculidae living in the Lake Uiam, was used as an experimental material and the embryonic development and the structure of glochidia of this species were investigated. This freshwater mussels was oviparous, but some ovoviviparous: incubated their youngs in the inner-demibranchs or outer-demibranchs, however, chiefly used the inner-demibranchs as brood-pouch. The average time required from a fertilized egg to two-cell stage, veliger stage, and glochidium was 76 minutes, 3 hours, and 17 hours, respectively, The mean size of glochidium was $168{\mu}m$ in shell height, $195{\mu}m$ in shell lengh, $114{\mu}m$ in hinge legth and the form of glochidium was D-type and had no hooks or hooklets for attaching to fish like Unioidae.

• Journal of Aquaculture
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• v.19 no.4
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• pp.254-260
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• 2006

A 6-week feeding trial was conducted to determine apparent protein and phosphorus digestibilities in order to evaluate nine different dietary protein sources in growing olive flounder, Paralichthys olivaceus. Nine diets containing fish meal analog ($BAIFA-M^{TM}$), white fish meal (WFM), flounder muscle powder (FMP), squid liver powder (SLP), leather meal (LM), soybean meal (SM), corn gluten meal (CGM), poultry by-product (PBP) or egg albumin(EA) were prepared by mixing a basal diet (BD) with one of nine test ingredients at the ratio of 7 to 3. Apparent protein digestibilities of FMP, SLP, WFM, SM, CGM, LM, PBP, $BAIFA-M^{TM}$, and EA were 94%, 92%, 86%, 82%, 75%, 72%, 72%, 71%, and 30%, respectively. Apparent phosphorus digestibilities of FMP, SLP, $BAIFA-M^{TM}$, LM, WFM, PBP, CGM, EA and SM were 77%, 72%, 65%, 55%, 54%, 50%, 20%, 20%, and 17%, respectively. Weight gain of fish fed FMP ($323^a$) was significantly higher than those of fish fed the other diets, and those of fish fed basal diet ($302^b$), SLP ($305^b$) and WFM ($308^b$) diet were significantly higher than those of fish fed SM ($274^c$), $BAIFA-M^{TM}\;(268^{cd}),\;PBP\;(261^{de}),\;LM\;(251^e),\;CGM\;(254^e)$ and EA ($181^f$). Based on the results of apparent protein digestibilities, apparent phosphorus digestibilities and weight gain, SLP, SM and $BAIFA-M^{TM}$ could be one of good protein source to replace fish meal in flounder diets.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.34-40
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• 2009

In fresh water fish hatcheries and farms, Saprolegniales often cause serious mortality to the fish and their eggs. Malachite green is an effective antifungal agent, but is carcinogenic to fish and humans. Alternative antifungal agents are needed. Presently, we tested various concentrations of MBT-01108 (Opuntia ficus-indica extracts) alone and in combination with bronopol, formalin and sodium chloride (MBT-01108 mixture) on in vitro mycelial growth and in vivo remediation of adult eel, Anguilla japonica, infected with Saprolegnia sp. and fertilized eggs of chum salmon, Oncorhynchus keta, to evaluate the compounds' antifungal efficacy on eyed-egg and hatching rates. MBT-Oll08 mixtures incorporating bronopol and formalin at respective concentrations of 50 and 30 parts per million (ppm), and 100 and 20 ppm were most effective in controlling Saprolegnia in vitro and in vivo (P<0.05). Repeated daily exposures to 50 ppm and 100 ppm MBT-01108 were more effective than exposure every 2-3 days post-fertilization for the inhibition of Saprolegnia infection of rainbow trout, Oncorhynchus mykiss eggs as compared with control (0 ppm).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.151-156
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• 1984

The Chili fish, one of the most common species of the freshwater fishes, is distributed in the river basins of the western coast of Korea. However, any studies on this fish, especially its development or life history, have not been made so far. The authors, therefore, carried out an experiment to reveal some characteristics of egg develoment and fry in this fish. For accomplshing this study, we caught some adult Chili fish by means of a casting net at raceway in the vicinity of Kunsan in June and July, 1983; then, we injected 0. 1 cc Gonadotrophic hormone 1,000 unit solution (Puberogen) in order to induce the spawning on the abdominal cavity of male and female respectively, Approximately 12 hours after injection, the artificially fertilized eggs by using of the dry method and the naturally fertilized eggs were observed simultaneously in the aquarium ($30{\times}50{\times}70cm$). The fertilized eggs, in spherical shape, were sperative, demersel, adhesive nature and $1.38{\sim}1.59\;mm$ in diameter. The light yellow yolk was opaque and $1.17{\sim}l.27\;mm$ in diameter. The hatching of eggs took place at 29.5 hours after fertilization under the condition of $23.5{\sim}25.0^{\circ}C$ water temperature. Basically there were not found so many different aspects in comparison with the common species of Cyprinidae in the development process of eggs : however, there were a few noticable characteristics, that is, pigment cells, eye balls and blood circulation are invisible, or the velocity of egg development is rapid, seemed similar to the Loach's egg. Newly hatched larvae with the yolk sac (2.39 mm in size) were $3.87{\sim}3.99\;mm$ in total length and their myotome number was expressed as 28+15=43. About 20 hours after hatching, a caudal and a pectoral fin as well as an anus began to orgin. In addition, a few malanophore showed on the upper regin of the yolk sac of the larvae whose size was 4.73 mm in total length. The larvae developed about 5.02 mm in total length, and the median fin fold in the abdomen extended forward to two thirds or beyond of the yolk sac at 50 hours after hatching. Simultaneously, the eye balls and mouth also appeared. After 3 days, the yolk sac nearly disappeared, and the larvae (5.4 mm in total length) with perfect eye balls began to swim for themselves for the first time. Also, the specialization between the gill arches and the ailmentary canal, the development of each fins except dorsal fin as well as the blood circulation obviously distinguished in this stage. The larvae whose total length was 5.68 mm was very brisk: also, the development of the dorsal fin rudiment, nearly perfect formation of each organs and the function of the upper and lower jaws were noticeably observed 5 days after hatching.