• Animal Systematics, Evolution and Diversity
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• 제19권1호
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• pp.49-55
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• 2003

중국새뱅이의 제1유생기를 상세히 기재하고 도시하였다. 중국새뱅이의 제1유생의 형태적인 특징을 아시아 지역에서 보고된 동 속의 다른 4종의 제1유생과 비교하였다.

• 한국양식학회지
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• 제20권3호
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• pp.194-198
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• 2007

Reproductive traits of Palaemon gravieri such as embryo size, number of embryo (fecundity), incubation period, larval development mode, larval development period, larval survival and larval growth were described and compared to analyze the correlation among those traits. Embryo volume is a primary factor determining other ensuing reproductive features. Egg volume was $0.042mm^3$ in the first developmental stage. Embryo volume in P. gravieri was comparatively small which is indicative of great number of embryo (y = 3.0161x + 0.0185 $R^2$ = 0.74 positive isometric relationship) and relatively long incubation period. Larvae survived from zoea 1 to post-larvae and it took 45 days at $22^{\circ}C$. Survival rate of the larvae was rather great in the early stage and thereafter steadily decreased. Daily growth rate of larvae in P. gravieri at $22^{\circ}C$ was 0.0195 mm on average. They grew steadily as time went by. Incubation period was between 10-14 days at $22^{\circ}C$. Larval development mode was almost complete planktotrophic. PNR (point of no return) appeared to be the third day on average. Survival rate of larvae without feeding declined rapidly between 3 and 4 days. Larval development period and stage frequency were 23-30 days and 11 stages which imply prolonged larval period and high mortality. The pattern of brood production followed fast successive parturial pattern. Most ovigerous female had mature ovary when they performed parturial molt soon after hatching (larval release).

• 한국어병학회지
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• 제21권3호
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• pp.167-174
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• 2008

Few studies on parasitic scutica-like ciliates (SLCs) influencing larval growth and survival during the seed production of the Japanese scallop, Patinopecten yessoensis have been performed in spite of relatively high magnitude of their infectious damage to the larvae. In the mass seed production of the scallop, SLCs were never infectious during D-larval stage which lasted 6 to 7 days. Indeed, the infection first occurred in 2 to 4 days after first umbo-staged larvae. A regular selection of active larvae in swimming behavior kept larval SLC infection low throughout the culture compared to unselected control (P<0.05) in which all the larvae alive were contained. Higher infection frequencies of the unselected control resulted in lower larval survivals and wider range of larval size distribution that drove larval attachment rate lower. To the worse, the nursery spats from the higher SLC infection exhibited a retarded growth and elevated occurrence of abnormal scallop.

• 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.

• 한국수산과학회지
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• 제34권4호
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• pp.378-383
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• 2001

실험에 사용한 성숙한 난소를 가진 산모양깔깔새우 (Metapenaeopsis dalei)는 1999년 8월 11일 충남 외연도 근해에서 새우조망을 이용하여 채집하였다. 산란한 유생을 4개의 염분구간과 3개의 수온구간 및 5개의 다른 먹이 조건에서 사육하여 이들의 생존율과 성장률을 비교하였다. 염분조건에서는 채집지의 염분과 유사한 30과 35에서 생존율이 높았고, 수온 조건에서는 산란 수온$24^{\circ}C$에서 생존율이 가장 높았다. 먹이 조건 실험에서는 식물성먹이에서 생존율과 성장이 동물성을 투여한 실험구보다 높았다.

• Animal cells and systems
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• 제10권1호
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• pp.7-14
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• 2006

Novactaea pulchella was reared in the laboratory, from hatching to the megalopal stage at $25^{\circ}C$. The larval stage of it consists of two zoeal and one megalopal stages. The first zoea of the present study differs from that described by Terada (1990) in the setal presence of the carapace, the maxilla and the maxilliped, and the lateral process on the abdominal somite. It is reported for the first time that brachyuran zoeas belonging to a species share two types of lateral processes on the abdominal somites. They are either on the abdominal somites 2 and 3 or on abdominal somites 2 to 5. A provisional key is provided to aid the identification of the actaeine zoeas in Korea and the adjacent waters.

• International Journal of Industrial Entomology and Biomaterials
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• 제30권2호
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• pp.45-49
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• 2015

The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae), is reared for commercial purposes as a live feed for animals. In 2011, it was officially introduced in Korea, and since then it has been considered commercially important. This beetle is a good animal feed resource because of its high protein content with balanced nutrients. However, its life stage characteristics have not been clearly described, especially of the larval stage that can be used as commercial products. To this end, in our study, we determined the number of Z. atratus larval instars, and described their characteristics at each stage, providing basic information about this beetle. Z. atratus larvae required eight to nine d of incubation period before hatching. The first instar period comprised three to four d. There were relatively large variations in each instar period, except for the first instar. Before the adults emerged, most of the individuals passed through15 to 18 instars. The highest pupation rate, 25.71%, was observed in both 16th and 17th instars. Body length gradually increased with each successive instar and it reached its maximum at the 18th instar. The color of larvae was white at the first instar, and gradually turned brown after the second instar.

• Animal Systematics, Evolution and Diversity
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• 제18권2호
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• pp.191-201
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• 2002

좁은뿔꼬마새우의 제1조에아 유생기를 상세히 재기재·도시하였다. 좁은뿔꼬마새우의 제1조에아 유생은 갑각에 두개의 앞배작은가시와 앞옆모가시를 가져 북방좁은 뿔꼬마새우, 긴좁은뿔꼬마새우 및 H. geniculatus보다 절좁은뿔꼬마새우와 상당히 가깝지만 제4-5배마디에 뒤옆가시를 가지지 않아 절좁은뿔꼬마새우의 제1조에아 유생과 분명하게 구별되었다. 한국근해에 보고된 꼬마새우과 종의 유생기재목록과 좁은뿔꼬마새우속 종에 대한 제1조에아 유생검색표가 제시되었다

• Animal Systematics, Evolution and Diversity
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• 제22권2호
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• pp.149-151
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• 2006

The larval stage of Ceraclea labulata (Martynov) is described for the first time. The larva can be distinguished from other known larvae of Korean Ceraclea by the absence of head marking and by the shape of frontoclypeus, which is equal in anterior and posterior width. The larval case is also described. Line-drawings of key characters and discussion on Korean Ceraclea are provided.

• Molecules and Cells
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• 제39권11호
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• pp.834-840
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• 2016

Caenorhabditis elegans (C. elegans) utilizes two different cell-cycle modes, binucleations during the L1 larval stage and endoreduplications at four larval moltings, for its postembryonic intestinal development. Previous genetic studies indicated that CDC-25.2 is specifically required for binucleations at the L1 larval stage and is repressed before endoreduplications. Furthermore, LIN-23, the C. elegans ${\beta}$-TrCP ortholog, appears to function as a repressor of CDC-25.2 to prevent excess intestinal divisions. We previously reported that intestinal hyperplasia in lin-23(e1883) mutants was effectively suppressed by the RNAi depletion of cdc-25.2. Nevertheless, LIN-23 targeting CDC-25.2 for ubiquitination as a component of E3 ubiquitin ligase has not yet been tested. In this study, LIN-23 is shown to be the major E3 ubiquitin ligase component, recognizing CDC-25.2 to repress their activities for proper transition of cell-cycle modes during the C. elegans postembryonic intestinal development. In addition, for the first time that LIN-23 physically interacts with both CDC-25.1 and CDC-25.2 and facilitates ubiquitination for timely regulation of their activities during the intestinal development.