• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.559-565
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• 2014

The fish and attached fish eggs by artificial floating island in lake Soyang was investigation from May to June 2013. The observed fish at the floating island during the survey period were Zacco platypus (5.2 %), Siniperca scherzeri (1.0 %), Lepomis macrochirus (90.8 %) and Micropterus salmoides (3.0 %) at the Cheongpyeong-ri, Cyprinus carpio (0.4 %), Z. platypus (54.6 %), L. macrochirus (20.3 %) and M. salmoides (24.7 %) at the Ungjin-ri. The collected species at the neighboring facility were 22 species belonging the seven families. Among them, exotic species such as Carassius cuvieri, L. macrochirus and M. salmoides. Also, Z. platypus (30.4 %), L. macrochirus (18.9 %), Opsariichthys uncirostris amurensis (15.4 %) and Hemibarbus labeo (9.3 %) were numberous. Attached fish eggs number were 708,800 (800 per $m^2$) at the Cheongpyeong-ri and 974,500 (1,100 per $m^2$) at the Ungjin-ri. The fish eggs number were 504,920 of the Carassius auratus (212,640 at the Cheongpyeong-ri, 292,280 at the Ungjin-ri) and 1,178,380 of the C. carpio (496,160 at the Cheongpyeong-ri, 682,220 at the Ungjin-ri). The hatched eggs number were 350,505 of the C. auratus(102,067 at the Cheongpyeong-ri, 248,438 at the Ungjin-ri) and 811,222 of the C. carpio (238,157 at the Cheongpyeong-ri, 573,065 at the Ungjin-ri).

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.2
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• pp.43-50
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• 2021

Growth tests on the Yuldo, Supum1 and Supum2 cultivars of Pyropia dentata were performed at the Eoran and Imha aquafarm, Haenam in Jeollanamdo, from October to December in 2017. The mean water temperature ranged from 5.4 to 26.4 ℃. In Eoran aquafarm (flating raft method), dissolved total nitrogen (DTN), dissolved total phosphorus (DTP), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) ranged from 0.091 to 0.181 mg/L, 0.007 to 0.019 mg/L, 0.114 to 0.187 mg/L, 0.008 to 0.033 mg/L and 0.200 to1.000 mg/L, respectively. In Imha aquafarm (fixed pold method), DTN, DTP, TN, TP and COD ranged from 0.118 to 0.276 mg/L, 0.005 to 0.024 mg/L, 0.155 to 0.305 mg/L, 0.009 to 0.042 mg/L and 0.300 to1.400 mg/L, respectively. In order to investigate the number of conchospores attached on the Pyropia net, which was cut into about 4cm long. The mean number of conchospores of Yuldo, Supum1 and Supum2 cultivars were 39.5, 26.5, 72.5, respectively. Young thalli were harvested two times at Eoran aquafarm, and three times at Imha aquafarm. In eoran aquafarm, the mean thallus length of Yuldo, Supum1 and Supum2 cultivars were 49.9, 46.0, 42.0 cm on October and 163, 126.0, 263.0 cm on November, respectively. The mean thallus width of Yuldo, Supum1 and Supum2 cultivars were 5.8, 4.6, 11.5 cm on October and 20.9, 11.5, 14.0 cm on November, respectively. In Imha aquafarm, the mean thallus length of Yuldo, Supum1 and Supum2 cultivars were 119.0, 60.9, 71.0 cm on October, 196.0, 132.0, 262.0 cm on November and 187.0, 281.0, 296.0 cm on December, respectively. The mean thallus width of Yuldo, Supum1 and Supum2 cultivars were 4.2, 3.4, 3.1 cm on October, 8.9, 6.2, 6.6 cm on November and 11.7, 11.6, 9.4 cm on December, respectively. In eoran aquafarm, contents of moisture, crude ash, crude lipid, crude protein and carbohydrate of three cultivars ranged from 11.64 to 20.15, 19.54 to 21.19, 0.00 to 0.18, 29.78 to 37.81, 29.16 to 29.71, respectively. In Imha aquafarm, contents of moisture, crude ash, crude lipid, crude protein and carbohydrate of three cultivars ranged from 8.43 to 9.15, 11.42 to 17.49, 0.00 to 0.00, 31.90 to 37.54, 36.30 to 42.24, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.370-374
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• 2015

Pacific herring Clupea pallasii eggs were attached to the gill net in Korean coastal waters off Busan. To conservation and management the eggs attached to the gill net, we followed the natural hatching in coastal waters from five days after fertilization to the hatching finished, where the temperature was $9^{\circ}C$. The diameter of fertilized eggs was 1.24-1.55 mm (n= 50), and had a segmented pale yellow yolk, no oil globule. Natural hatching had started by 10 days after fertilization. Mass hatching occurred around 11-12 days after fertilization, most of eggs separated from the gill net. Therefore, when the Pacific herring eggs attached in gill net, should be natural hatching-induced in coastal waters during 12-14 days.