• 한국해양학회지
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• 제23권4호
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• pp.184-193
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• 1989

황해(黃海) 중동부(中東部) 연안역(沿岸域)의 부유성(浮游性) 어란(魚卵) 군집(群集)을 연구하기 위하여, 1985년 7월부터 1986년 6월까지, 천수만(淺水灣)에서 금강(錦江) 하구(河口) 부근에 이르는 13개 정점에서 봉고 네트로 부유성(浮游性) 어란(魚卵)을 채집하였다. 19개 분류군의 부유성(浮游性) 난(卵)이 채집되었는데, 이중 7개 분류군은 종(種) 수준까지, 2개 분류군은 과(科) 수준까지 동정되었다. 멸치(Engraulis japonica)는 전체 난 출현량의 89.5%를 차지하였으며, 청보리멸(Sillago japonica)이 2.5%, 전어(Clupanodon punctatus)가 2.4%, 밴댕이(Herklotsichthys zunasi)가 1.7%, 돛양태류(Callionymidae spp.)가 1.6%를 차지하여, 이들 5개 분류군이 총 출현 난(卵)의 97.7%를 점하였다. 부유성(浮游性) 난(卵)은 4월부터 10월 사이에 출현하였으며, 6, 7월에는 출현량이 절정을 보이고 있으나, 멸치 난이 집중 출현하기 때문에 종(種) 다양성(多樣生)이 낮았다. 또한 부유성 난의 출현 양상으로부터 각 어종별 산란 수온범위를 추정하였다.

• Fisheries and Aquatic Sciences
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• 제26권4호
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• pp.256-267
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• 2023

The suitability of any fish species for successful aquaculture requires basic information on its reproduction and growth. This study investigated some facets of the reproductive biology of Synodontis shall (Mochokidae) from River Siluko in Nigeria. Fish samples were collected forth-nightly for a duration of fourteen (14) months-March 2015 to April, 2016 with the assistance of artisanal fishermen. Fishes were identified using taxonomic guides and standard techniques were used for determination of sex ratio, gonad maturation and fecundity. Linear regression method was used to define the correlation between fecundity and fish length, body weight and ovary weight. Results showed that sex ratio did not indicate a significant divergence (p > 0.05) from the 1 male to 1 female distribution ratio (1:1.41). Gonad morphology revealed paired gonads. Testes and ovaries were classified into four maturity stages: immature, resting, ripening and ripe. Gonadosomatic index ranged from 0.04 to 5.68 (males) and 0.03 to 20.19 (females). Absolute fecundity ranged from 1,014 to 4,520 eggs (mean = 2,592 eggs) and did not correlate significantly (p > 0.05) to ovary weight. This study has contributed to existing data on the biology of freshwater fish species in Nigeria and provided valuable information for fishery management tools in the conservation and utilization of this valuable freshwater fish species.

• 한국수산과학회지
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• 제53권4호
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• pp.486-491
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• 2020

This study was investigated the survival and hatching rate of fertilized eggs in olive flounder Paralichthys olivaceus at water temperature, salinity, duration of transport and different stock densities during commercial transport. The observed optimal temperature during transport was 17.5℃ similar to the natural environmental conditions. The proper salinity was observed to be at 33 psu (practical salinity unit) in both surviving and hatching rate. In terms of the duration of transport, there were no differences until 12 hours between survival and hatching rate, but shorter time of transport would be better. With the best conditions during transport, 20,000 eggs/L were handled in both survival and hatching rate. These results can be essential in the production and transport of healthy olive flounder seeds.

• Fisheries and Aquatic Sciences
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• 제1권1호
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• pp.68-71
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• 1998

The egg structure and shape of the skin parasite, Entobdella hippoglossi from the Atlantic halibut, Hippoglossus hippoglossus was examined using scanning electronic microscope. The newly produced eggs of E. hippoglossi were yellowish in color and tetrahedral in shape. The eggs were entwined together in a complicated chain-like fashion by a long filament. The appendage showed the presence of buoy-like structures. The buoy-like structures on the appendage of the eggs of E. hippoglossi in the present study were totally different from other sticky droplets. It is suggested that these structures are not sticky droplets but buoys for floating eggs which have entwined together on the bottom of the sea. It seems that these buoy-like structures may be needed for preventing the eggs from being covered by mud or particles and thus maintaining the eggs in an oxygenated environment.

• 한국수산과학회지
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• 제50권3호
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• pp.287-295
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• 2017

Egg development and morphological change of larvae of the Sakhalin sole Limanda sakhalinensis were studied by observing specimens obtained in a rearing experiment from fertilized eggs to the juvenile stage. The wild broodstock was collected in January 2010 and kept in a circular water tank (${\O}1.5{\times}1m$) at a temperature of $14.5{\pm}0.5^{\circ}C$. Fertilized eggs ranged from 0.72 to 0.82 mm ($0.77{\pm}0.07mm$, $mean{\pm}SD$) in diameter. The eggs were spherical, transparent and adhesive demersal. The egg yolk was divided from the oocyte 10 min after fertilization (AF), and an embryo was formed in 36 h AF. More than 50% of the eggs hatched within 133 h AF. The mouth and anus did not open until $3.5{\pm}0.25mm$ total length (TL). At 4, days after hatching (AH), the fish became larvae 3.7 to 4.2 mm ($4.0{\pm}0.36mm\;TL$), yolk absorption was completed and the mouth began to open. The left eye moved upward and the nostril moved to the right at 39 days AH. These post-larvae ranged from 8.0 to 9.9 mm TL ($8.9{\pm}1.33mm\;TL$). At 50 days AH, the fish became juveniles ($12.4{\pm}1.20mm\;TL$) There were 70-72 dorsal fin rays, 55-56 anal fin rays, 11 pectoral fin rays, and 6 ventral fin rays and the juveniles adopted a benthic life.

• 한국가축번식학회지
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• 제18권3호
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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.

• 한국발생생물학회지:발생과생식
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• 제6권2호
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• pp.71-76
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• 2002

최첨단 연구로 성장하고 있는 해양생물공학 연구 중 염색체공학 연구의 배수체 조작, 성분화, 자성 발생, 형질전환 어류와 유전자 조작에 관한 최근의 연구 동향을 분석하고 향후 발전 방향에 관하여 살펴보았다. 배수체 연구 중 3배체 어류 생산 연구는 20여종의 어류들 중 무지개 송어와 메기가 물리적 충격을 이용한 실험법으로 산업적으로 이용 가능한 수준에 있다. 성분화를 포함한 약 15종의 고급 어종이 방사선 투사법에 의해 자성 발생 2배체를 생산 유도하였다. 형질전환 어류는 1985년 이래 약 40여종의 어류가 외래 유전자를 미세 조작이나 전기충격법에 의해 형질전환되고 있다. 최근에 역바이러스성 벡터들에 의한 외래 유전자를 이용한 형질전환 어류가 생산되었으며 이러한 형질전환 어류는 기초과학 육성은 물론 해양생물공학 연구의 발전이 기대되고 있다.

• 한국어류학회지
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• 제3권1호
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• pp.11-23
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• 1991

월성 주변 해역의 부유성 난 자치어 분포를 조사하기 위하여, 1989년 11월과 1990년 2월, 5월, 7월의 4회에 걸쳐 봉고네트로 부유성 난과 자치어를 표층채집 하였다. 본 해역에서 출현한 부유성 난은 멸치, 돛양태류, 앨퉁이, 전어와 기타로 분류되었는데, 조사기간 중 앨퉁이와 돛양태류는 전체 어란 출현량의 60.1%와 13.7%를 차지하여 우점종으로 나타났다. 자치어는 총 21개 분류군이 출현하였다. 조사기간 중 멸치는 전체 자치어 출현량의 61.2%를 차지하여 극우점종으로 나타났으며, 돛양태류가 11.9%를 차지하여 우점종으로 나타났다. 그 이외에도 앨퉁이, 망둑어류, 까나리, 볼락, 개볼락, Scartella cristata, 쏨뱅이가 주요 출현종을 이루었다. 이들 9개 분류군은 총출현량의 96.5%를 차지하였다. 본 해역은 용승이 자주 발생하는 지역으로 용승으로 인한 표층수의 이동은 부유성 난이나 자치어의 분포에 영향을 미치는 것으로 나타났다.

• 한국가금학회지
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• 제26권4호
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• pp.217-236
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• 1999

Among polyunsaturated fatty acids (PURAs) targeted for manipulation in animal tissues (poultry eggs and meat), omega-3 PUFAs(n-3 PUFAs) are discussed in this review. 3 or 5% dietary menhaden oil (MO) supplemented layer diets was reported to increase docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents in the egg. MO at 1.5% also increased the deposition of up to 180mg total omega-3 fatty acids / yolk. Utilization of 5% ground flax seed (FS) resulted in similar total omega-3 fatty acid (FA) deposition as 1.5% MO. However, the basic feed formulations used in the Canadian feed industry usually include 10 to 20% FS in the egg laying diets. Recently several studies reported that addition of tocopherols in layer diets increased the tocopherol content more in the egg than any other tissue. One of reports said that 3.5% dietary oil with added tocopherols resulted in increasing tocopherol deposition and FA composition of the egg and other tissues. In the poultry meat, redfish meal (RM;4, 8, 12, 15 and 30% of diet) or redfish oil (RO;2.1 or 4.2% of diet) added to the practical corn-wheat-soybean based diets resulted in an increase in omega-3 FA and docosapentaenoic acid (DPA) contents in broiler meat lipids. Linseed oil (LO;1.0, 2.5, and 5.0% of broiler diet) supplemented in broiler diets also resulted in omega-3 FA and the ratio of omega-6 being significantly higher in poultry meat lipid than MO. Concern about fish flavor resulted in research about fish oil (FO) supplementation in broiler diets. Without the use of antioxidants, no more than 1.5% FO should be fed to broilers due to unacceptable orders from the chicken carcasses. One recent research project found that over 50mg/kg of vitamin E was required for maintaining the stability of unsaturated lipids in the meat. In regards to 'fishy'or 'crabby'taint in the eggs and poultry meat, poultry products remained acceptable when dietary fish oils were stabilized with antioxidants.

• Parasites, Hosts and Diseases
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• 제58권6호
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• pp.647-652
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• 2020

Clonorchis sinensis is the most common fish-borne intestinal parasite in Korea. The aim of the present investigation was to survey the status of C. sinensis infection and analyze associated risk factors in residents of Haman-gun, Gyeongsangnam-do. A total of 5,114 residents from 10 administrative towns/villages voluntarily agreed to participate in the study, which comprised fecal examination, a questionnaire survey for risk factors, ultrasonography, and enzyme-linked immunosorbent assay for cancer biomarker detection in the blood. We detected C. sinensis eggs in 5.3% of the subjects. By region, Gunbuk-myeon had the highest number of residents with C. sinensis eggs. The infection rate and intensity were higher in male than in female residents. Based on the risk factor questionnaire, infection was highly associated with drinking, a history of C. sinensis infection, and the practice of eating of raw freshwater fish. Extension of the bile duct, infection intensity, and cancer biomarker detection significantly correlated with the presence of eggs in the study population. In conclusion, the development of feasible, long-term control policies and strategies for the elimination of C. sinensis in Korea is still required.