• Korean Journal of Poultry Science
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• v.20 no.2
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• pp.55-64
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• 1993

The experiment was conducted to compare the effects of supplements of copper, vitamin I and selenium on growth and immune responses of broiler chicks fed cornsoy diets. The basal diet contained 21% crude protein, 2,800 kcal ME, 10 mg Vitamin E, 10 mg copper and 0.1 mg selenium per kg diet. Additions of the basal diet were copper (150mg and 250 mg/kg) or combination of vitamin I(200 mg/kg) and selenium(2 mg/kg). Serum immunoglobulin G(IgG) concentrations and body weight gain were determined weekly from hatching to 7 weeks of age. Additions of copper(150mg, 250mg) to the basal diet were showed, at the four weeks of age, 4.8% and 4.5% higher in body weight gain than that of control group, respectively. The active immune system of copper and (Vit. E＋Se) treated groups developed one week earlier than control group(basal diet). Negative correlation between IgG concentration and body weight gain was showed at the period from hatching to three weeks of age and, thereafter, positive correlation were identified (p＜0.01). Mortality rates were observed lower in all treated groups than that of control. In conclusion, the lower the levels of serum IgG, at the first two weeks of age, the lower in disease Infection and the higher in body weight gain.

• Journal of Aquaculture
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• v.7 no.4
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• pp.207-223
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• 1994

Induction of triploid cherry salmon, Oncorhynchus ma.sou was performed by the heat shock procedure. The triploids were induced by 15 and 20 min heat shock treatments after 10 min fertilization at $28^{\circ}C$. Incidences of the triploidy were $91.4\%\;and\;89.8\%$, respectively. Nucleus and erythrocyte from the induced triploids larger than those of the diploids in major axis, minor axis, major axis/minor axis, surface area and volume. The chromosome number of diploid was 2n= 66 (17 pairs of metacentrics or submetacentrics, 16 pairs of acrocentrics or telocentrics), and that of triploid was 3n=99. Satellites were observed in the short arm of the largest telocentrics, and these may be useful marker to determine the polyploidization. Diploid have outgrown to triploid, and female have also outgrown to male in the triploid group during the 22 months of observation period after hatching. During the spawning season, 22 to 26 months after hatching, diploid were observed the growth retardation because of their sexual maturation, however the triploid showed continuous growth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.1
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• pp.46-53
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• 2010

Spawning behavior and early life history of the tuman river sculpin, Cottus hangiongensis were studied in the laboratory and in the field at Wangpi Stream, Gyeongsangbuk-do, Korea, from January to December, 2007. The spawning ground was in the lower Wangpi Stream, which is a shallow region about 40cm or less in depth. During the spawning period, from March to April, mature males made nest cavities under stone 10 which they led a gravid female. The male and female then turned upside down, and spawning and fertilization occurred onto the ceiling of the nest cavity. After spawning, the male chased the female from the nest and mated with several other females. Fertilized eggs were spherical in shape, demersal, adhesive, transparent and yellow in color, measuring 1.86 mm (1.79~1.93 mm) in diameter. A mean of 17(12~22) various-sized oil globules were counted in the yolk. Granular materials formed a mass in the yolk. Fertilized eggs hatched at 256 hrs, 10 minutes after the morula stage under water temperature of $15.0{\sim}18.0^{\circ}C$. Newly hatched larvae 9.34 mm (9.02~9.69 mm. n=10) in total length (TL) had a large yolk At 14 days after hatching, larvae 11.40 mm (11.07~11.72 mm, n=10) in TL transformed to the postlarval stage. At 41 days after hatching, postlarvae of 18.42 mm (17.31~18.62 mm, n=10) in TL had reached the juvenile stage. The result of this study indicate that Cottus hangiongensis has the spawning ground in the lower stream and the amphidromous life history which is the different from that of Cottus poecilopus.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.105-111
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• 2004

When the clitellate tiger worms(Eisenia fetida) were fed with paper mill sludge, sewage sludge of agricultural-urban area and sewage sludge of agricultural area, number of cocoons produced by individual clitellate earthworm for 104 days were 11.8, 8.6 and 3.5, respectively. However, clitellate earthworms that had been fed with sewage sludge of agricultural-urban area for 52 days or fed with sewage sludge of agricultural area for 95 days could not produce cocoons, whereas the earthworms that were fed with paper mill sludge kept producing cocoons through the investigating period. The hatchability of cocoons produced by the clitellate tiger worms(Eisenia fetida) fed with sewage sludge of agricultural-urban region, sewage sludge of agricultural region and paper mill sludge were 42.8%, 38.3% and 39.2%, respectively. And hatching periods of cocoons were 33.8~36.0 days, which were not affected by the kinds of sludges. However, the cocoons produced by clitellate earthworms which had been fed with sewage sludge for about 1.5 months could not hatch at all. Death rates of second generation hatched from cocoons produced by tiger worms(Eisenia fetida) which had been fed with the sewage sludge from agricultural-urban region and the sewage sludge from agricultural region reached to 100% and 90% at 60 days after hatching, respectively, whereas death rate of second generation fed with paper mill sludge reached to 16%.

• Korean Journal of Ichthyology
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• v.24 no.2
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• pp.110-117
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• 2012

Hatching date and early growth of Pacific cod Gadus macrocephalus were estimated by examination of otolith microstructure of Pacific cod juveniles collected in Jinhae Bay of Korea from May to June, 2008. Water temperature during the main spawning time ranged from 7 to $9^{\circ}C$ according to the geographic distribution of temperature measured from November to May between 2006 and 2009. The spawners were collected from December to February between 2006 and 2008, and the gonadosomatic index of spawners was larger in females than in males, showing a peak in January. Total length of juveniles ranged from 37.5 to 94.9 mm ($63.2{\pm}11.0mm$; mean${\pm}$SD). The number of daily growth increments in juvenile otoliths were on average $102{\pm}15$ in May 17 samples, $119{\pm}16$ in May 29 ones and $116{\pm}18$ in June 3 ones. Hatching dates estimated from the number of daily growth increments ranged from late December to mid-March, showing the peak between late January and mid-February. Daily growth in total length (TL, mm) can be adjusted to the Gompertz curve: $TL_t=123.2{\exp}\{-{\exp}[-0.0165(t-81.8)]\}$ ($r^2$=0.93, n=273).

• 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.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.69-73
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• 2001

Observation of morphological changes during larval and juvenile stages of the halfbeak fish, Hyporhampus sajori (Temminck et Schlegel), was made based on samples of fertilized eggs collected on the shores of Youngil Bay, Phohang-shi, Korea, on May 27, 1991, and incubated in the laboratory. During the incubation period, water temperature fluctuated between $17.6^{\circ}C$ and $23.2^{\circ}C$. The newly hatched larvae were elongated and 7.0~8.50 mm in total length (TL) with 40~42+17~18 = 59~60 myotomes. Numerous melanophores were on the head, mid-dorsal part of the body, intestine, and the tail part of the notochord. Three days after hatching the larvae had attained 8.60~10.90 m in TL, had completely absorbed the yolk, and the caudal notochord was flexed $45^{\circ}$ upward. At this time, it was attained postlarvae stage. Thirty-seven days after hatching the postlarvae were 32.37~44.95 mm in TL and had reached the juvenile stage. All fins were formed with a complete set of fin rays with the following counts: dorsal fin rays 16~17; pectoral f in rays 6; ventral fin rays 12~14; caudal fin rays 11~12+11~12 = 22~24.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.380-386
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• 1986

Snailfish, Liparis tanakai (Gilbert et Burke) is widely distributed in the coastal waters of Korea and Japan. On December 21, 1985, fertilized eggs of the fish were collected from the coastal waters of Saryang-do island, Kyongsangnam-do, Korea, and the eggs were incubated and the larvae reared at a mean water temperature of $9.2^{\circ}C$ in the laboratory. The fertilized eggs of this species are demersal, adhesive and spherical in shape, measuring $1.68{\sim}1.78mm$ (mean 1.72mm, n=30) in diameter, containing about 20 oil globules. Hatching took place 21 days after blastula stage. During the incubation period water temperature fluctuated between $8.1^{\circ}C\;and\;11.8^{\circ}C$. The newly hatched larvae were $5.70{\sim}6.41mm$ (mean 6.10mm, n=30) in total length with $7{\sim}9$ (abdominal) and 36 (caudal) myomeres. Many melanophores were distributed on the large pectoral fin, yolk sac and peritoneum. Twelve days after hatching, the larvae attained $5.85{\sim}6.46mm$ in total length, and at this time the larvae absorbed the yolk almost completely. Melanophores appeared on the snout and the posterior part of head.

• Journal of Aquaculture
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• v.11 no.4
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• pp.565-572
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• 1998

Survival rate of larval red spotted grouper, Epinephelus akaara is very low, because mouth size of the larvae is too small to eat normal sizes of rotifers. In order to enhance larval survival, optimal culture conditions for larvae using different live foods and water temperatures were studied. Bigger live food produced larger size of rotifer, when the rotifer was cultured with three different live foods such as Tetraselmis tetrathele, marine Chlorella and Nannochloris oculata. Also, the size of rotifer produced was temperature-dependent showing that higher water temperature induced smaller rotifer. Survial rate of the larvae increased with the increase of water temperature up to $29{\circ}C$. Also, higher larval survials were found at the food density of 15 to 20 individuals per milliliter. The larvae fed L-type or small individuals of L-type rotifer died all within a week, although the larvae fed S-type or small individuals of S-type one survived successfully during this period. The size of small individuals of S-type rotifer collected through fine net became larger in a few hours within larval culture tank. Survival rate of grouper larvae with initial stocking density of 40 thousands in 6-ton concrete tank was 6.3% in 10 days and 0.2% in 53 days after hatching, respectively. Total length of the larvae reached around 29.5 mm in 53days after hatching.

• 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.