• Fisheries and Aquatic Sciences
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• 제8권2호
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• pp.90-96
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• 2005

The larvae of Palaemon gravieri were reared in the laboratory at three different temperature regimes ($15^{\circ}C,\;20^{\circ}C,\;and\;25^{\circ}C$) with the salinity ranges (28-32 psu) to understand how temperature and body size influence survival rate, and growth components (molt increment and intermolt period). The optimum temperature for the highest survival rate was $25^{\circ}C$. The intermolt periods consistently increased with an increase in size and instar number; however, the molt increments at successive instars generally decreased with an increase in size and instar number. The shortest intermolt period and the highest larval growth rate both occurred at $25^{\circ}C$. Thus, the optimum temperature for larval survival and growth rate was found to be $25^{\circ}C$ which was the temperature at which the larvae actually appear in nature.

• 한국어병학회지
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• 제17권2호
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• pp.139-144
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• 2004

범게의 zoea 및 megalopa기 유생에 있어 수온의 영향을 파악하기 위하여 수온변화에 따른 이들의 생존, 성장 및 탈피주기를 조사하였다. Zoea 및 megalopa기 유생에서 실온과 $20^\circ{C}$에서 82.5%와 80%로 높은 생존율을 나타내었다. 성장률은 수온이 높을수록 양호한 경향을 나타내어 $30^\circ{C}$에서 zoea 및 megalopa기 유생의 성장률은 각각 185.0% 및 41.6%를 나타내어 $15^\circ{C}$구간의 101.6% 및 23.7%에 비해 유의한 성장 증가를 나타내었다. 탈피주기는 온도에 반비례하여 수온이 높을수록 빨라지는 경향을 나타내어, $30^\circ{C}$ 설정 실험구에서 zoea 및 megalopa기 유생에서 각각 16.4일 및 9.2일을 나타내어 $15^\circ{C}$의 24.4일 및 15.2일과 비교하여 유의적 차이를 나타내었다.

• 수산해양교육연구
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• 제29권2호
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• pp.422-435
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• 2017

Intermolt periods, growth rates, survival (%) and relative growth of the megalopa larvae of Portunus trituberculatus (Miers, 1876) were studied up to the crab 7th stage for 160 days in the 3 different temperature groups in which each has 60 larvae. The higher the water temperature was the shorter the intermolt period was in each crab stage. In addition, a deviation of intermolt periods was shown as few as the water temperature gets higher. The intermolt period in the 7th crab stage was $29.8{\pm}3.26$ days in the experimental group at the room temperature, $45.2{\pm}3.89$ days at the temperature of $17^{\circ}C$, and $25.6{\pm}2.23$ days at the temperature of $27^{\circ}C$, respectively. The survival (%) of larvae of P. trituberculatus (the crab 7th stage) is the highest in the group at the room temperature: However, they showed 15% at the temperature of $27^{\circ}C$ and 10% at the temperature of $17^{\circ}C$. All the groups were shown the similar relative growth, but significant differences appeared in some comparison. The sizes (mean growth of carapace width) of the crabs in the group at the temperature of $27^{\circ}C$ reached 5.01~25.45 mm length (it is the longest among the groups) from the crab 1th to the crab 7th stage. However, the sizes (mean growth of carapace width) of room temperature were 4.99~22.26 mm and the size of crab in the group at the temperature of $17^{\circ}C$ reached 4.8~17.26 mm, The sizes (mean growth of carapace length) of the crabs in the group at temperature of $27^{\circ}C$ reached 2.88~13.56 mm, However, the size of the crab in the group at the room temperature showed 2.88~12.34 mm, while in the group at temperature of $17^{\circ}C$, their average growth of carapace length were 2.51~8.03 mm. The growth rates of larvae of P. trituberculatus (from the crab 1th to the crab 7th stage) were changed with the increase of the instar stage, however their changes showed irregular.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.308-314
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• 2010

Larvae of Palaemon serrifer were reared in the laboratory under three different temperature regimes ($15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$) to study the effects of rearing temperature on larval survival and growth, as well as other traits such as embryo volume, number of embryos (fecundity), incubation period, development. Mode and development period. Growth pattern was analyzed by measuring the molt increment and intermolt period. The intermolt period consistently increased with size and instar number and was shortest at $25^{\circ}C$. However, molt increments generally decreased with instar number. Number of embryos varied from 552 to 1355. The relationship between the number of embryos and carapace length was expressed by the equation (fecundity) y=2.7744x+0.208 ($R^2$=0.7961). Egg volume was a primary factor affecting other life-history traits. Egg volume was $0.078\;m^3$, which is relatively small thus embryos exhibited a relatively short incubation period and a comparatively short development period, and the nutritional mode was planktotrophic. Brood production was followed by a fast parturitional pattern. Most ovigerous females had mature ovaries when the parturial molt occurred soon after eclosion.

• 한국양식학회지
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• 제14권1호
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• pp.51-56
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• 2001

At 5$^{\circ}C$ incubation of the brooded eggs of the snow crab, Chionoecetes opilio lasted for 297 days; freshly hatched prezoea molted to become the first zoea in one hour. Length (from the tip of the rostral spines to the tip of the dorsal spines) of the first and second zoeae measured 4.8 and 6.4mm, respectively. Experimental rearing of the larvae at 5, 10, 15 and 2$0^{\circ}C$ indicated that the upper limit of thermal tolerance is 15$^{\circ}C$, as all the reared larvae succumbed at 2$0^{\circ}C$. Intermolt period from the first the first zoea to the second was 57, 32 and 23 days at 5, 10 and 15$^{\circ}C$, respectively and that of the second zoea was 52, 29 and 90 days, respectively. Largest number of larvae survived at 1$0^{\circ}C$.

• 한국양식학회지
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• 제17권1호
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• pp.58-61
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• 2004

이 연구에서는 경남 통영에서 채집된 남방도화새우, Pandalus gracilis 유생의 적정 사육 온도와 수온이 성장에 미치는 영향을 파악하기 위해 10와 2$0^{\circ}C$(32.5∼34.5$\textperthousand$; 12L: 12D)두 온도 구간을 설정하여 이루어졌다. 유생의 생존율은 2$0^{\circ}C$가 1$0^{\circ}C$에 비해 높게 나타났으며, 유생의 탈피주기는 1$0^{\circ}C$에서 보다 긴것으로 나타났다.

• 한국수산과학회지
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• 제37권3호
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• pp.186-191
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• 2004

The effects of temperature on the growth of larvae of wrinkled swimming crab (Liocarcinus corrugatus) under controlled laboratory conditions of 15, 20 and $24^{\circ}C$ were investigated (33.5 psu: 12L: 12B). Each specimen was maintained individually, the instar size was determined from exuvia, and the survival and intermolt period of each instar were recorded. There were no significant differences (P>0.05) in the survival rates at 15, 20, and $24^{\circ}C.$ Comparison of survival over the first 27 days between the three temperature regimes showed significant differences (P<0.001). The intermolt period increased with the instar number, and was greatly extended at the lowest temperature. The molt increment varied little with temperature, and had a mean value of $21.35\%$ over the whole study. Temperature had little effect on survival and molt increment.

• Applied Microscopy
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• 제38권2호
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• pp.97-105
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• 2008

탈피에 따른 거미 과립혈구의 미세구조 변화를 고배율의 투과 전자현미경으로 관찰하였다. 산왕거미(Araneus ventricosus)의 과립혈구는 산호성 과립혈구(EGs)와 염기호성 과립혈구(BGs), 그리고 혈색소혈구 (cyanocytes) 등 세 종류가 구분되었다. EGs와 BGs는 공통적으로 전자밀도가 높은 구형 과립을 함유하고 있었지만, 과립의 크기와 미세구조의 차이에 따라 두 종류가 확연히 구분되었다. 과립의 크기가 작은 EGs는 탈피기간중 세포소기관의 다양한 형태적 변화가 나타나며, 왕성한 식작용을 통해 많은 식포를 형성하는 것으로 관찰되었다. 반면, 과립의 크기가 큰 BGs의 세포질에서는 식포가 관찰되지 않았으나, 탈피시기 동안 과립의 전자밀도가 낮아지는 특성이 관찰되었다. 가장 대형의 과립혈구인 혈색소세포의 세포질에는 많은 헤모시아닌 결정체가 동심원상으로 배열되어 있었으며, 탈피기간중 혈구의 일부는 불규칙한 구조로 변형되었다. 고배율의 투과전자현미경으로 헤모시아닌 결정체의 격자구조를 관찰한 결과, 미세소관(microtubule)과 매우 유사한 구조를 가지고 있었으며, 각각의 미세한 관상 구조는 다시 약 20여 가닥의 극히 미세한 필라멘트로 이루어져 있음이 확인되었다.

• 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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• 제23권2호
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• pp.93-108
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• 1990

범게, Orithyia sinica(Linnaeus)의 유생을 Zoea 1기에서부터 Crab 13기까지 사육하여 생잔율, 탈피간격기간, 성장을 기별로 측정 연구한 결과는 다음과 같다. 1. 탈피간격기간은 령기에 따라 증가하나 Crab 5기에서부터 성특징이 나타나는 시기전인 Crab 7기까지 감소하였다가, 성특징이 나타나는 시기 이후부터 급격히 증가한다. 수온에 따른 탈피간격기 간의 변화 양상은 유사하나 실온의 경우 변동의 폭이 컸다. 2. 유생의 생잔율은 Megalopa기까지 $20^{\circ}C$구간에서 사육한 것이 $86.6\%$, 실온에서 사육한 것이 $80.0\%$였다. Crab의 생잔율은 $20^{\circ}C$의 경우 Crab 13기까지 부화후 약 540일간 사육한 것이 $45\%$, 실온의 경우($11.0\~27.7^{\circ}C$) Crab 12기까지 부화후 약 540일간 사육한 것이 $10\%$였다. 생잔율의 성별 차는 없었 다. 3. 유생기의 크기는 사육온도구간별 크기가 있어 실온 구간($21.0\~24.0^{\circ}C$)에서 사육한 Zoea 2, 3기유생은 $20^{\circ}C$구간에서 사육한 유생들 보다 $0.62\~4.03\%$ 작았다. 4. Crab의 갑폭, 체중은 사육 온도구간에 차가없이 1기에서 10기까지 동일하게 증가하고 11기부터는 $20^{\circ}C$에서 사육한 Crab들의 크기가 커지는 경향을 보인다. 체중의 증가 양상은 제9기에서 성장이 감소되었다가 10기에서부터 다시 증가한다. 5. 갑장으로 측정한 성장율은 Zoea 1, 2기에서 각각 $35.65\%,\;41.41\%$였으며 Zoea 2기의 성장률이 높았다. 6. 령기에 따른 성자율 값의 변화는 령기의 중가에 따라 감소 경향이 있으나 증감변동이 일정하지 않고 Crab 5기까지 감소하다가 Crab 6기 이후 약간 증가하였다가 Crab 10기 이후 다시 감소하는 경향을 보였다. 7. Crab $1\~13$기까지의 평균 성장율은 갑장의 경우 $23.87\%$($18.00\~30.91\%$), 갑폭 $23.99\%$($17.82\~30.48\%$), 체중 $91.51\%$($58.86\~129.14\%$)이였으며 성장율은 사육 온도구간별 차는 없었다.