• Environmental Analysis Health and Toxicology
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• v.21 no.4 s.55
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• pp.311-316
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• 2006

미꾸리(Misgurnus anguillicaudatus)에 대한 4가지 농약(diazinon, carbaryl, fenpropathrin, myclobutanil)의 급성독성을 평가하기 위하여, 치어 및 자어 단계(postlarva I, postlarva II, 8 WPH(weeks posthatch), 16 WPH, 20 WPH, 32 WPH, 40 WPH)의 미꾸리를 사용하여 급성독성실험을 실시하였다. 각 생육단계 별로 구해진 각 실험농약의 96-hr $LC_{50}$값을 비교하여 미꾸리에 대한 급성독성이 높은 순서를 정리한 결과는 Fenproparthri>Diazinon>Carbaryl, Myclobutanii 순으로 나타났다. 또한, 본 연구에서 사용된 4가지 농약의 독성은 미꾸리의 생육단계에 따라 차이를 나타냈다. 농약에 대한 감수성이 민감한 미꾸리의 생육단계 순으로 정리하면 Postlarva I>Postlarva II, 8 WPH>16 WPH, 20 WPH, 32 WPH, 40 WPH 나타났다. 그러므로 환경관리 및 규제목적으로 미꾸리 성체를 사용하여 독성실험을 할 경우에는 독성을 과소평가 할 수도 있음을 보여주었다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.3
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• pp.264-269
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• 2021

A single postlarva (9.72 mm in standard length) specimen of Crossorhombus azureus (Alcock, 1889) belonging to the family Bothidae, was collected using a bongo net from the southern sea of Korea on December 10, 2019. This species is characterized by having spines on post basipterygial processes. It has two eyes located at the opposite side in head, which accordingly belongs to pre-metamorphosis stage. Melanophores are distributed on the dorsal and anal fin base on the right side (blind side), which is regarded as a useful identification key distinguishing C. azureus from congeneric species in their postlarval stage. A molecular analysis based on mitochondrial DNA COI sequences showed that our specimen was closely matched to adult C. azureus (K2P distance = 0.017). As there is no Korean name for the genus Crossorhombus in spite of presence of Crossorhombus kobensis and its Korean name "Go-be-dung-geul-neob-chi" in Korea, we proposed a new Korean name "Dung-geul-neob-chi-sog" for the genus Crossorhombus and "Pa-lang-dung-geul-neob-chi" for the species C. azureus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.378-383
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• 2001

Larvae of Metapenaeopsis dalei (Rathbun) were successfully spawned and reared in the laboratory under controlled conditions. The experiments were designed to examine effects of salinity (20, 25, 30 and 35), temperature (21, 24 and $27^{\circ}C$ ) and food (five items) on larval development, survival and growth, Salinity affected larval survival, from $\%$ at 20, to $60\%$ at 35 (protozoea 1 to first postlarva), The highest survival rate was obtained at $35\%_{\circ}$. Temperature affected larval survival, from $46\%$ at $27^{\circ}C$ to $54\%$ at $21^{\circ}C$(protozoea 1 to first postlarva). The highest survival rate was obtained at $24^{\circ}C$. Mortality was the highest from protozoea 1 to protozoea 3, but decreased considerably for all temperatures once the mysis stage was reached. Larval growth was affected by different of food items. Phytoplankton (Isochrysis galbana) was the optimum food for the larval survival and the growth from protozoea 3 to first postlarva.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.450-455
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• 1996

To investigate the food organisms of the shad (Konosirus punctatus) during the postlarval stage, the gut contents of the shad, captured in Kwangyang Bay in June 1990, were observed. The food organisms food items of the shad larvae of $4.8\~5.0mm$ (NL) were copepod eggs and copepod nauplii, whereas those of the larvae longer than 5.0 mm (NL) were copepod nauplii and Tintinnopsis.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.82-89
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• 2013

The spawning behavior, development of eggs and larvae of the Five striped damselfish, Abudefduf vaigiensis were studied. The Five striped damselfish were caught at Dolsan Island, Yeosusi, Jeollanamdo from May in 2011. As a result of observation, male fish attracted female after cleaning the rock. Female left after spawning and male protected their eggs until they had hatched out. The fertilized eggs were elliptical in shape (mean long diameter: 1.06 mm; mean short diameter: 0.55 mm) and transparent. Larvae hatched at 53 hrs after fertilization in $24.5{\sim}26.5^{\circ}C$(mean $25.0^{\circ}C$). The newly hatched larvae were 2.55~2.86 mm (mean 2.71 mm, n=10) in total length and their mouth and anus were already opened. They began to eat rotifer and transformed to postlarva stage. 3 days after hatching postlarva was measured 2.74~2.97mm(mean 2.84 mm, n=10) in total length. 10 days after hatching postlarva was measured 3.85~4.20mm(mean 4.00 mm, n=10) in total length with dosal fin rays IV-5; ventral fin rays I-3; caudal fin rays 1~2.

• Korean Journal of Ichthyology
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• v.34 no.4
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• pp.225-230
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• 2022

The single postlarval specimen (7.53 mm in standard length) of Thalassoma quinquevittatum (Lay & Bennett, 1839), belongs to the family Labridae, was collected by a bongo net from the southern coastal waters of Jeju-do Island, Korea in November 2020. T. quinquevittatum has a deeply curved dorsal contour before the dorsal fin, the oval eyes, and no melanophores throughout the body. While T. amblycephalum has a slightly curved dorsal contour before the center of the dorsal fin, the circular eyes, and few melanophores on the body. A molecular analysis based on 548 base pairs sequences in the mitochondrial DNA cytochrome c oxidase subunit I region shows that the specimen was closely matched to adult T. quinquevittatum (K2P distance=0.002-0.005). We report the first record of T. quinquevittatum in Korean waters, and suggest its new Korean name "Da-seot-jul-saek-dong-nol-rae-gi".

• Journal of Aquaculture
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• v.21 no.4
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• pp.339-345
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• 2008

Farming of the fleshy shrimp Fenneropenaeus chinensis which is a major cultured species in the west coast of South Korea, has been suffered :trom mass mortality due to disease epizootics including viruses. Since the Pacific white shrimp Litopenaeus vannamei was introduced to Korea in 2003, farming of this species has rapidly increased for years, occupying 62.5% of total cultured shrimp production in 2007. However the studies on L. vannamei culture methods for shrimp farming situations in Korea are very limited. Nursery culture of shrimp larvae has some advantages including increased survival, improved feed efficiencies, enhanced growth performance and reduced grow-out period. In this study, L. vannamei postlarvae (${PL_3}-{PL_{10}}$) with a density of $3,750-9,090/m^3$ were cultured in four raceways under limited water exchange condition for 35 days. Survival was the highest (93.6%) in tank stocked with $4,090/m^3$ and was the lowest in tank with $9,090/m^3$ (58.1 %). Mean body weight at harvest ranged from 0.071 to 0.108 g, and FCR was 0.59-0.70 in all tanks. Concentration of total ammonia nitrogen was increased up to 20 ppm on day 10 in all tanks and thereafter gradually decreased by the third week of culture. Nitrite-nitrogen was rapidly increased from the third week, representing bio-floc condition by developed nitrifying bacterial community. Of the present nursery system some modification of structure and consideration for commercial scale are needed in order to be implemented to shrimp farmers.

• Korean Journal of Ichthyology
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• v.27 no.1
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• pp.1-9
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• 2015

The morphological and skeletal development and larvae and juvenile of Sebastes koreanus were studied. The Sebastes koreanus were caught at Yeosu-si, Jeolla-namdo from March in 2014. Larvae beared at water temperature of $13.5{\sim}15.5^{\circ}C$ (mean $14.5{\pm}0.1^{\circ}C$). The just beared larvae were 6.38~6.43mm(mean $6.40{\pm}0.02mm$, n=5) in total length and their mouth and anus were already opened. They began to eat rotifer and transformed to postlarva stage. 5 days after bearing postlarvae was measured 6.45~6.49 mm (mean $6.47{\pm}0.02mm$) in total length. 15 days after bearing postlarvae was measured 6.55~6.72mm(mean $6.64{\pm}0.08mm$) in total length. 60 days after bearing juvenile was measured 15.5~20.0 mm (mean $17.7{\pm}2.25mm$) in total length with dorsal fin rays X IV-12~13; anal fin rays III-7; caudal fin rays 16.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.1-10
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• 1998

The early history of Korean mandarin fish, Siniperca scherzeri was studied to obtain some information required in aquaculture and reinforcement of natural population. During the period from June 1996 to July 1997, the mature adults of Siniperca scherzeri were collected from the middle Soyang Lake at Puksan - myon, Chunchon - shi, Kangwon - do, Korea. The eggs from females were obtained by injecting HCG or/and GnRH - a and fertilized by dry method in the laboratory. The fertilized eggs, measuring 1.70~2.10 mm in diameter and expanded to 2.20~2.66mm after absorption of water, were globosity, light orange yellow, separative, submergence and had one large oil globules of 0.5~0.7 mm. The blastodisc was formed in 1 hour and cleavage started in 1 hour 30 min. after fertilization, and the intervals of each stage of cleavage was about 50 min. at the water temperature of $21{\sim}24^{\circ}C$. Hatching occurred 131 hours 30 min. after fertilization and newly hatched larvae were 5.86~6.85 mm in total length(TL) and numerous stellate melanophores were distributed on the yolk and abdomen of caudal peduncle. The yolk was almost absorbed and the teeth development. 3 days after hatching, at 6.98~7.60 mm TL. The head spines and the teeth were largely developed and all fins were completely formed and became postlarva stage 15 days after hatching, at 10.10~12.90 mm TL. The body shape and the color pattern were similar to adult, 25 days after hatching, at 15.3~23.8 mm TL. In 5 months after hatching were reached at 154.10~175.02 mm TL and 49.32~82.67 g in body weight.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.52-61
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• 2017

The egg development and early life history of Korean endemic fish, Squalidus multimaculatus (Gobioninae), were investigated. The eggs from the females were obtained by injecting 10 IU/g of human chorionic gonadotropin and inseminated by wet method in the laboratory. The fertilized eggs were 0.8~0.9 mm in diameter and had no oil globules. The embryo began to hatch about 65 hrs after fertilization under water temperature of $24{\pm}1^{\circ}C$. The newly-hatched larvae were 2.5~3.1 mm in total length, and their mouth and anus were not opened. Four days after hatching, the postlarva were 4.0~4.2 mm in total length, and their york sacs were completely absorbed. They entered the juvenile stage when all fin-rays were formed at 30 days after hatching, and their total length were 11.2~15.7 mm. At 45 days after hatching, the external from of juveniles were similar to those of adults (total length were 18.8~22.5 mm), and 80 days after hatching, the external characteristics from of juveniles were same to adults (total length were 25.7~35.9 mm).