• Animal Systematics, Evolution and Diversity
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• 제32권2호
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• pp.133-140
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• 2016

The first zoeas of Parapanope euagora and Halimede fragifer hatched in the laboratory from two ovigerous galenid crabs of Pilumnoidea were collected from Jindo Island, Jeolanam-do, southern Korea. Their morphologies are described in P. euagora for the first time in the world and re-described in H. fragifer with the color images of live zoeas. In this study, they show a general morphology of Pilumnoidea by having a long antennal exopod, an endopod of the maxillule with 1, 2+4 setae, an endopod of the maxilla with 3+5 setae, and a fork of the telson with two lateral armatures. However, the first zoea of P. euagora differs from other known zoeas of pilumnoid species including H. fragifer by having a long antennal exopod with a medial seta and spine, not two spines, and a fork of telson with two lateral setae, not a seta and spine. Such characteristics of the antennal exopod and the fork of telson are reported for the first time in the pilumnoid zoeas. A comparison between the first zoeal stage of H. fragifer in this study and that of Terada shows minute differences in the characteristics of the antennule and the fork of telson.

• 한국양식학회지
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• 제6권3호
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• pp.159-171
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• 1993

대하의 2oea와 mysis 기의 성장과 생존에 대한 밀도, 빛, 수온, 먹이의 영향은 다음의 조사결과와 같다. 사육 밀도에 따른 유생의 생존율은 500마리/l에서 보다 200, 300마리/l일때 휠씬 높았고, 사육밀도 100, 200, 300, 500마리/l일때 생존율은 90.3, 95.2, 94.3, $86.7\%$ 이었다. 규조를 혼합하여 먹이로 공급한 광주기 실험에서는 24시간 연속 조명하였을 때 생존율이 $96.5\%$로 자연광을 이용할 때 $(79.0\%)$와 24시간 암흑 처리할 때 $(4.3\%)$에 비해 매우 높은 생존과 빠른 성장을 보였다. 사육 수온은 $19^{\circ}C$에서 $97.3\%$의 생존을 보였지만 $22^{\circ}C$에 비해 성장이 늦었으며, $22^{\circ}C$에서 $96.7\%$ 의 생존율과 빠른 성장을 보였다. 수온 $25^{\circ}C$에서는 $51.6\%$의 생존율로 $19,\;22^{circ}C$에 비해 생존율과 성장이 저조하였다. 먹이생물로는 6종의 규조(A. normaii, C. nomaii, C. simplex, N. clostuium, P tricomutum, S. costatum, T weissflogii)를 혼합하여 공급하였을 때, 연속 조명으로 사육할 경우, $97.3\%$의 가장 높은 생존율과 최고의 성장을 나타내었으며, 1종의 규조만을 먹이생물로 공급하였을 때에는 S. costatum을 공급하였을 때의 생존율 $82.1\%$, T. weissflogii의 $80.6\%$ 를 제외하고는 모두 $62\%$이하의 생존율과 저조한 성장을 나타내었다.

• 한국수산과학회지
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• 제44권3호
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• pp.243-250
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• 2011

The effects of food, temperature, salinity, and rearing density on the survival and growth of the swimming crab Portunus trituberculatus, were studied. With regard to food, the larval survival rate to zoea IV was the highest (53.9%) in the mixed feed group (rotifers+ Artemia), followed, in order, by the rotifer, commercial feed, and Artemia groups. The growth of young crabs reared on different diets was the highest in group VI. The survival rate to zoea II at 20 to $30^{\circ}C$ ranged between 77.2% and 83.1%, and was the highest for crab I (17.3%) at $25^{\circ}C$. When young crabs were cultured individually at four different temperatures (20, 25, 30, and $35^{\circ}C$), the growth did not differ significantly at 25 to $30^{\circ}C$, but was higher than at $20^{\circ}C$. The survival rate of larvae to crab I was 12.7 and 11.4% at 25 and 28 psu, respectively, while all of the larvae died at 15 psu. For young crabs, there was no significant difference in growth and survival from 20 to 30 psu. The survival rate decreased with increasing rearing density from zoea I to crab I. Each molting cycle took 1 month from crab I to VIII. Subsequently, the interval increased with growth. The mean body weight of crab XV after 24 months was $428.05{\pm}57.63\;g$.

• 한국어병학회지
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• 제8권2호
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• pp.157-164
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• 1995

꽃게의 종묘생산시에 많이 이용되고 있는 chlamydomonas sp.를 접종한 green water에서 자연광선조건하에 산소포화도와 pH의 변화가 이들 zoea유생에 미치는 영향을 조사하였다. 사육수의 pH와 산소포화도는 양자 모두 일출과 함께 상승하여 일몰과 함께 저하하는 규칙적인 주야간의 변동을 보였고, pH 8.6 이상으로 조절하였던 실험구의 pH는 최고 9.5 이상으로 상승하였다. 또한 chlamydomonas sp. 농도가 310만 cell/cc 이상인 실험구의 산소포화도는 주간에 118% 이상으로 상승하였으나, 야간에는 급격히 감소하여 100% 이하로 저하하여다. 꽃게 zoea유생의 가스병은 실험개시 4시간후 pH와 산소포화도가 각각 8.5, 118%이상에서 출현하여 수온 및 산소포화도의 저하와 함께 회복하는 경향을 나타내었으나, pH 및 산소포화도의 상승과 함께 연일에 걸쳐 출현하였다. 꽂게 zoea 유생의 사망은 가스병이 관찰된 시점 (pH$\geq$8.5, 산소포화도$\geq$118%)에서부터 발생하기 시작하여 수온, pH 및 산소포화도가 상승할수록 증가하였다.

• 한국양식학회지
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• 제6권4호
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• pp.273-284
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• 1993

동남참게, Eriocheir japonicus 유생의 수온 및 염분 농도에 따른 이온 농도, 삼투질 농도 및 산소 소비에 대한 실험 결과는 다음과 같다. 체액의 $Na+$ 및 $Cl^-$ 이온 농도는 저염분 농도 ($30\%$ 해수) 이하일 때는 저온 $(16^{\circ}C)$에서 더 높았고, 고염분 농도 ($90\%$ 해수)일 떼는 고온 $(30^{\circ}C)$에서 더 높았다. 유생 령기가 어릴수록 매질의 염분 농도와 수온에 따른 체액의 이온 농도 변화폭이 컸다. 체액의 $K^+$ 이온 농도는 매질의 염분 농도의 영향을 많이 받았으나 수온의 영향은 거의 없었다. 체액의 삼투질 농도는 모든 유생 령기들에서 매질이 $70\%\;(24.5\%o)$ 해수 농도일 때 거의 등장액을 나타내었다. 개체당 산소 소비는 모든 실험구에서 zoea 1, 2령기에서 특히 낮았고, $70\%$ 해수 농도에서 모든 령기들의 산소 소비가 가장 높았다.

• Fisheries and Aquatic Sciences
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• 제27권3호
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• pp.180-194
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• 2024

Mass mortalities of mud crab Scylla spp. larvae due to pathogenic Vibrio spp. outbreaks have frequently occurred in hatcheries. To overcome this problem, probiotics containing Bacillus subtilis bacteria are applied to inhibit pathogenic ones. We tested different doses of probiotic-containing B. subtilis (10⁸ CFU/g) on the Scylla tranquebarica larvae and investigated the microbiota population, including Vibrio. Water quality, larvae development, and crablet production were also monitored. The recently hatched larvae were grown in twelve conical fiber tanks filled with 200 L sterile seawater, with a salinity of 30 ppt at a stocking density of 80 ind/L. Four different doses of probiotics were applied in the larvae rearing, namely, A = 2.5 mg/L, B = 5 mg/L, C = 7.5 mg/L, and D = 0 mg/L, with three replicates. Next-generation sequencing analysis was used to obtain the abundance of microbes in the whole body of megalopa and the water media for larvae rearing after applying probiotics. Sixteen Raw Deoxyribonucleic Acid samples (eight from a whole body of megalopa extraction from four treatments of probiotics defined as A, B, C, D, and eight from water media extraction from four treatments of probiotic defined as E, F, G, H) were prepared. Then, they were sent to the Genetics Science Laboratory for NGS analysis. Ammonia, nitrite, total organic matter (TOM), larvae, and crablet production were monitored. Based on the Next-generation sequencing analysis data, the Vibrio spp. decreased significantly (p < 0.05) than control test (D) in megalopa-applied probiotics at the doses of 2.5 mg/L (A) and 7.5 mg/L (C) and in the water media for megalopa rearing treated with probiotics at the dosage of 5.0 mg/L (F). Ammonia in the zoea stage in B treatment and TOM in the zoea and megalopa stage in B and C treatments were decreased significantly (p < 0.05). It impacts the higher number of zoea survival in treatments B and C. Finally, it results in a significantly high crablet production in treatments B and C. Therefore, the dosage of 5 mg/L to 7.5 mg/L improves crablet S. tranquebarica production significantly.

• Animal cells and systems
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• 제6권2호
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• pp.89-93
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• 2002

The first zoeal stage of Macromedaeus orientalis (Takeda et Miyake, 1969) is described and illustrated. Its morphological characteristics are compared with those of other known species of the subfamily Xanthinae. The first zoeas of M. orientalis and M. distinguendus are similar, but they can be distinguished from each other by the characteristic of antenna. The former has a smooth antenna with a rounded tip, while the latter has a serrated antenna with a spinous tip.

• 수산해양기술연구
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• 제45권4호
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• pp.251-259
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• 2009

Swimming crabs, Portunus trituberculatus(Miers) are commercially important off the coasts of Korea, Japan and China. Harvest of swimming crabs has been fluctuated along their distribution ranges. Fluctuations in the interannual harvest of swimming crabs may be correlated with the survival rate during the larval period. The survival rates, intermolt periods, and growth of larval swimming crabs were investigated in the laboratory. Larval swimming crabs are released and undergo development from April to August off the western coast of Korea in the Yellow Sea. Sea surface temperatures off the western coast of Korea during the larval season were used for the laboratory experiments, and ranged from 22 to 26${^{\circ}C}$. Larvae were individually cultured at four different temperatures, 22${^{\circ}C}$, 24${^{\circ}C}$, 26${^{\circ}C}$, and 28${^{\circ}C}$. Zoea molted to megalopa at all temperatures and developed to the first crab stage at 24${^{\circ}C}$, 26${^{\circ}C}$, and 28${^{\circ}C}$. Survival rates from zoea I to the first crab stage increased with increasing temperatures. Intermolt period and the growth rate of the mean carapace length were inversely correlated with temperature. Our research helps understand the changes in survival rate and growth of larval swimming crabs resulting from changing oceanic temperatures. Further, our study suggests that the fluctuations in fishery harvest of swimming crabs off the coast of Korea may be related to changes in larval survival affected by changing ocean conditions.

• Animal Systematics, Evolution and Diversity
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• 제9권2호
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• pp.69-86
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• 1993

무늬발개의 유생을 수온 $25^{\circ}C$, 염분농도 33.3$\textperthousand$의 해수에서 사육하고, 전체 유생기의 형태적인 특징을 상세히 기술 및 도시하였다. 본 종은 5 zoea와 1 megalopa 유생기를 가지며, 부화시부터 megalopa와 제1기 crab까지는 각각 18일과 31일이 걸렸다. 무늬발개 제 1 zoea 유생은 갑측극이 있고, 미절과 제2촉각의 형태가 각각 B형이며, 제1소악과 제2소악의 내지가 각각 1+5, 2+2의 강모를 가지는 점은 이미 보고된 풀게속의 다른 유생들의 특징과 일치하고 있다. 풀게속의 유생 상호간의 구별될 수 있는 형태적인 특징들, 특히 측엽을 가지는 복부마디의수, 구기 부속지들의 강모식에 대하여 토의하였다.

• Animal cells and systems
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• 제5권4호
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• pp.275-281
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• 2001

The zoea1 stages of Philyra kanekoi Sakai, 1934 were obtained by laboratory rearing. Three zoeal stages were described and illustrated in detail. Zoeal morphology was compared with those of other described species of the family Leucosiidae. Morphological comparisons with congeneric species revealed that zoeas of P. kanekoi were more similar to those of P. pisum and P. platychira than to other Philyra. The present material could be distinguished from other Philyrinae species by having no dorsal carapace spine, a spinous tip of the antenna, and no chromatophore on the base of a dorsal carapace spine. Within the family Leucosiidae, the zoeas of three Philyra (P. kanekoi, P. pisum and P. platychira) showed the greatest affinities with Leucosia sima and L. pubescens (Leucosiinae), and the number of setae on the basipod of the first maxilliped could be very useful characterisitcs for indentification between Philyra and Leucosia zoeas.