• Title/Summary/Keyword: Molt increment

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Survival Rate and Growth of Palaemon gravieri Larvae Reared in the Laboratory (Decapoda: Caridea: Palaemonidae)

  • Kim, Sung-Han
    • Fisheries and Aquatic Sciences
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    • v.8 no.2
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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.

Effects of Temperature on Larval Growth and Survival in the Wrinkled Swimming Crab (Liocarcinus corrugatus) (Brachyura: Portunidae) Reared in the Laboratory (주름꽃게 (Liocarcinus corrugatus) 유생의 성장과 생존에 대한 온도의 영향)

  • KIM Kwang Bong;HONG Sung Yun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.3
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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.

Effects of Rearing Temperature on Larval Survival and Growth and on Reproductive Traits of Palaemon serrifer (Decapoda: Caridea: Palaemonidae)

  • Kim, Sung-Han
    • Fisheries and Aquatic Sciences
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    • v.13 no.4
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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.