• Journal of Aquaculture
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• v.17 no.3
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• pp.221-227
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• 2004

In the present study, we investigated the effects of food and salinity on growth and survival of river puffer, Takifugu obscurus offsprings in indoor land-based tank during the early development. In the food experiment, the river puffer larvae (TL 8.7$\pm$0.1 mm, BW 20.0$\pm$3.2 mg) were fed with tubificid, Limnodrilus gotoi, water flea, Daphnia carinata, mysid, Neomysis awatschensis, Manila clam, Ruditapes philippinarum and artificial food together Artemia nauplii for 30 days, and the growth and the survival of larvae were investigated. In the salinity experiment, the river puffer larvae and juvenile at three stages (Stage I: TL 5.8$\pm$0.4 mm; Stage II: TL 12.0$\pm$0.2 mm, Stage III： TL 44.5$\pm$0.7 mm) were supplied with Artemia nauplii, water flea and/or artificial food and were reared in 0, 10, 20 and 30 psu at respective stages. The results shows that the growth rates of larvae feeding with artificial food and tubificid together Artemia nauplii were higher than those of larvae in other groups, but the survival rates of larvae feeding with water flea and mysid together Artemia nauplii were higher than those of larvae in other groups. In salinity, the results shows that the growth and survival rates of offsprings were significantly higher in 10∼20 psu than those in 0 and 30 psu at Stage I and n. At Stage III, the growth and the survival rates were the highest in 20 psu, but the lowest in 0 psu. However, it should be noted that the rates in 0 and 30 psu were significantly enhanced at Stage III in comparison with those at Stage I and II. Therefore, it is concluded that river puffer, T. obscurus is euryhaline marine species, which can normally grow and live at salinities from 0 to 30 psu, and that a combinative supplement with Artemia nauplii and water flea, D. carinata may confer an advantage on growth and survival of the river puffer offsprings in indoor land-based tank.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.86-93
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• 1981

For daily supply of rotifers to feed juvenile fish and/or larval crustaceans such as shrimp in their seedling culture procedures, the maximum daily increase of cultured rotifers in relations with the inoculation densities of rotifers and the concentrations of food organism, Chlorella sp. were initially investigated in an experimental culture unit. The best results were obtained from the 10 inds./ml of the rotifer inoculation density with $3\times10^6\;cells/ml$ of Chlorella showing the maximum daily increase of 73.0 inds./ml/day on the 7th day. Based on the best results of the initial experiments a trial was made for continuous daily harvests of rotifers. As in the initial experiments, the maximum daily increase of rotifer was observed on the 7th day, when the daily harvest was initiated and continued once a day for 6days. For the 6 days, the amount of the mean daily harvest was $1.42\times10^5$ individuals per culture flask ($3{\iota}\;filled\;with\;2{\iota}$culture water) shelving a possibility of continuous daily harvests.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.2
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• pp.193-199
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• 2015

We observed that the growth and physiological change in Haliotis discus discus by low-dose irradiation with gamma ray.Irradiation with gamma ray was undertaken by using the low-level irradiation facility ($^{60}CO$) in cooperation with the Institute of Nuclear Science and Technology at Jeju National University. The parent abalones were attached one by one and then fixed by using the rubber band to the front side of the fabricated case for irradiation with gamma ray. The experimental plots of irradiation with gamma ray were set as 10, 15, 20 and 25 Gy and the 25 female abalones and 10 male abalones were utilized for each experimental plot. The sperms and eggs were fertilized by setting an interval for each dose to prevent mixing with other experimental plots when fertilizing the sperms and eggs for each dose of irradiation with gamma ray. As for the fertility, it was confirmed to be 85% the control and 10 Gy groups, whereas it was found to be 80%, 65% and 50% in the 15 Gy, 20 Gy and 25 Gy groups, respectively. As a conclusion, the hatching rate and attachment rate were higher at 10 and 15 Gy than the other experimental plots, and the growth rate was higher at 20 Gy than the other experimental plots. Also the changes in lysozyme activity in accordance with the stress of water temperature were found to have a significant increase in the other experimental plots as compared with the control plot at the end of 0 h. The changes in lysozyme activity have remained constant in all the experimental plots at the end of 12 h. These results allowed us to confirm that lysozyme was undertaking the biodefense action by reacting sensitively to the stress of water temperature in the control experimental plot. As for the other experimental plots, they are believed to avoid the biodefense mechanism due to the high degree of anti-parasite mechanism and anti-viral mechanism. Thus, it is believed that it would be imperative to conduct development and research on breeds that were potent for environmental tolerance by applying the method of irradiation with gamma ray to other marine animals and plants.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.308-316
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• 1987

The flying fish, Prognichthys agoo, is widely distributed in the coastal waters of south-eastern Korea. On July 14, 1986, mature adults of flying fish were captured from U-do, Cheju-do. The eggs were stripped and fertilized by the wet method on the ship. The mature eggs are demersal and adhesive with 30-40 filaments. The egg diameter varied from 1.42 to 1.58 mm. The water temperature throughout incubation ranged from 23.70 to $27.82^{\circ}C$, and salinity was maintained at $30.75-33.76\%_{\circ}$. The hatching took place in 174 hours after fertilization. The newly hatched larvae measured 4.75-5.25 mm in total length possessing yolk sac and about 45-46 myotomes. The larvae cultured for ten days after hatching reached 11.45-12.60 mm in total length and entered the juvenile period of life. Twenty days after hatching, the juveniles measured 20.01 mm in mean total length, and the scales were formed behind the pectoral fin.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.1
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• pp.30-34
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• 2018

Niemann Pick type C disease (NPC) is an inherited progressive neurodegenerative disorder, due to defects of intracellular lipid trafficking and storage. Hepatosplenomegaly may prevail, while progressive neurodegenerative symptoms such as cerebellar involvement, dystonia, vertical supranuclear ophthalmoplegia, cataplexy, and eventually seizures starting at juvenile or late infantile period may accompany after normal early development. Here we describe a 3-year-old Korean boy with NPC who presented with splenomegaly at age 3. Liver biopsy showed characteristic foamy cell stained by periodic acid-schiff, and molecular analysis for NPC1 identified the compound heterozygous mutations, novel mutation of c.1631G>A (p.Trp544Ter) and c.2662C>T (p. Pro888Ser) as a known mutation. Filipin was strongly stained with unesterified cellular cholesterol in the patient's skin fibroblasts. The patient has received migulstat since age 3 years and his long-term outcome is needed to be observed.

• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.64-79
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• 2015

We investigated the tidal current, hydrographic data, and benthic environment of major sea cucumber (Holothuroidea, de Blainville, 1834) habitats in Baengnyeongdo, Jindo and Uljin to understand the optimal environmental or ecological habitat for sea cucumbers. The three study areas were characterized by a cold-water mass of temperatures ranging $12{\sim}18^{\circ}C$, with an active circulation between the surface and deep waters. According to an analysis of the tidal current map, a strong flow velocity of $100{\sim}120cm\;s^{-1}$ appeared in Baengnyeongdo and Jindo. The three sea cucumber habitats showed the common characters of a bottom sediment composed of sand-silt, a diverse seaweed colony and benthic organisms, and boulders and rocks which provide a hideout for the organisms. We aimed to draw the optimal habitat condition for sea cucumbers in Korea, and the result showed that the low water temperature, rapid water flow, active vertical mixing between surface and deep waters, bottom composed by sand-silt, large rocks, and diverse seaweed colony and benthic organism were important factors. The optimal habitat for Juvenile sea cucumbers was the intertidal areas characterized by a muddy bottom, reef, and seaweed. The optimal habitat for adult sea cucumbers was characterized by a place where sand and mud are mixed, and the body size of the sea cucumber was proportional to water depth, and the relatively large boulders and rocks compared to the intertidal area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.633-642
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• 1994

Distribution of ichthyoplankton in the adjacent waters to Kori were surveyed during the period from April, 1991 to January, 1992. The dominant fish eggs included the eggs of Engraulis japonica, Maurolicus muelleri, Callionymus spp. and others. The eggs of Engrualis japonica and Maurolicus muelleri were $79.52\%$ and $1.86\%$ of the total eggs abundance, respectively. A total of 15 taxa of fish larvae were found. The dominant species was Engraulis japonica accounting for $52.39\%$ of the total larvae and followed by Callionymidae fish($29.36\%$). Other major species were Stephanolepis cirrhifer($6.30\%$), Sebastes schlegeli($3.16\%$), Ammodytes personatus($1.33\%$) and Girella punctata($1.70\%$). These 6 taxa constituted $94.30\%$ of the total larvae collected. In this area, distributions of warm water had a great influence on larvae and juvenile distribution which usually is along the coast and the other places where there layer water movements since, upwelling in the open sea affects ichthyoplankton distribution.

• Korean journal of applied entomology
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• v.51 no.1
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• pp.33-37
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• 2012

This study was conducted to investigate food preference and developmental characteristics of the gray field slug, $Deroceras$ $reticulatum$ M$\ddot{u}$ller (Stylommatophora: Limacidae) using various foods. The food preference of $D.$ $reticulatum$ was most highest on Chinese cabbage ($Brassica$ $campestris$ L., followed on cucumber ($Cucumis$ $sativus$ L.), and significantly low on beet ($Beta$ $vulgaris$ var. Ruba), kale($Brassica$ $oleracea$ L. var. $acephala$ D.C), carrot (Daucus carota L.) and Chinese cabbage ($Brassica$ $campestris$ L.) which were not different significantly. The total number of eggs laid by $D.$ $reticulatum$ was the highest (n = 109.6) on cucumber and the lowest (n = 10.1) on leaf perilla ($Perilla$ $frutescens$ var. $japonica$ Hara). Hatchability was the highest (92.4%) on cucumber and the lowest (62.5%) on leaf perilla. The egg developmental period was not significantly different from 12 days to 13 days among host plants. Juvenile period and adult longevity ranged from 75 days to 111 days and 66 days to 187 days, respectively. Thereby, life span from egg to adult longevity of $D.$ $reticulatum$ was the longest on cucumber with 273 days and the shortest on 190 days on leaf perilla.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.61-70
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• 1997

The spawning season, growth and feeding habit of tubesnout, Aulichthys japonicus were examined from the samples collected by a small beam trawl in the Zostera marina belt at the coastal water off Hamduck, Cheju Island, from May 1993 to May 1994. Tubesnout was the dominant species of overall 58 species collected in the study area throughout the year. The larvae and juvenile of tubesnout in the frequency distributions of body length began to appear in the Z. marina belt in March, and adults disappeared after May in the following year. The gonad weight index (GWI) and the condition factor (K) were high from November 1993 to January 1994 for males, while females were high from February to May 1994. Although tubesnout is an oviparous fish, males have the urogenital papilla. These results suggest that they were fertilized between November and January, and then males seemed to be died or move into other places. Females were examined to spawn from February to May. The stomach contents of tubesnout were dominated by copepoda smaller than ca. 1mm, Paracalanus, Oithona, Acartia, Oncaea and Harpacticoidae, accounting for 97% of total food items. The feeding habit of tubesnout did not vary by size. The fishes fed on Calanus, Euchaeta and decapoda larvae larger than ca. 3mm in March and April during the spawning season.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.48-60
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• 1997

The species composition and seasonal variations of fish community in the Zostera marina belt at the coastal water off Hamduck, northern part of Cheju Island, were analyzed based on day and night samples collected by a small beam trawl from May 1993 to May 1994. The dominant species among the 58 fish species in 35 family were tubesnout, Aulichthys japonicus, gobie, Pterogobius zonoleucus, filefish, Rudarius ercodes, pipefish, Syngnathus schlegeli and sea catfish, Plotosus lineatus. These species comprised 86.1% in the number of individuals and 62% in biomass. The number of individuals and biomass were high between October and December, and low between January and April. About 90% of fishes were noncommercial and small-sized fishes, less than 14cm in total length. The larvae and juvenile fishes were collected in the study area throughout the year. The recruitments of dominant species were related to the seasonal variations of Z. marina utilized as a shelter or feeding ground. A japonicus, P. zonoleucus, Zoarchias glaber and Hexagrammos agrammus recruited between January and June, and R. ercodes, S. schlegeli, P. lineatus and Petroscirtes breviceps between July and December.