• Title/Summary/Keyword: Starvation of hatching larvae

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Effect of Starvation on the Just Hatched Grass Puffer, Takifugu niphobles Larvae (절식에 따른 복섬, Takifugu niphobles 부화 자어의 성장, 생존율 및 간세포 핵 크기에 미치는 영향)

  • Park, In-Seok
    • Journal of Marine Life Science
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    • v.2 no.1
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    • pp.27-33
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    • 2017
  • The effects of starvation on the growth, survival and hepatocyte nuclear size of the just hatched grass puffer, Takifugu niphobles larvae were studied. The total length of the larvae showed increase up to 3 days after hatching (DAH), however, 3th to 6th DAH, the starved group grew, slower than the fed group, significantly. The body weight of the fed group grass puffer showed increase steadily during experimental period. The body weight of the starved group showed increase until 3th DAH, however, after 3th DAH the growth of body weight showed minute decrease. The survival of starved group decreased more significantly lower than that of the fed group and all the larvae died on the 6th DAH (p < 0.05). The nuclear area of the hepatocytes in the starved group were not significantly different from those of the hepatocyte nuclei in the fed group to 3th DAH, however, the starved group showed histological differences with smaller hepatocyte nuclear size compared with the fed group from the 4th to 6th DAH. Results form this study can be used as an indicator of the nutritional status of grass puffer larvae.

Effects of Starvation and Delayed Feeding on Growth and Survival of Pacific Cod Gadus macrocephalus Larvae (대구, Gadus macrocephalus, 자어의 첫 섭식 시 기아와 늦은 먹이 공급이 성장과 생존에 미치는 영향)

  • Shin, Min-Gyu;Lee, So-Gwang;Jeon, Hae-Ryeon;Joo, Jae-Hyeong;Gwak, Woo-Seok
    • Korean Journal of Ichthyology
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    • v.31 no.1
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    • pp.7-15
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    • 2019
  • The present study aimed to investigate the influence of starvation on growth, survival and swimming ability of Pacific cod Gadus macrocephalus larvae. Notochord length, musculature height, body depth, gut height and volume of yolk of reared larvae were measured to determine the growth parameters. A significant difference was observed in all morphometric characteristics before 15 DAH (days after hatching). Body depth and volume of yolk of unfed larvae were significantly smaller than those of fed larvae from 9 DAH (P<0.05). Almost all yolk in fed group was consumed at 11 DAH. Survival and growth of larvae were observed to determine the effect of delayed initial feeding (2 DAH, 3 DAH, 4 DAH, unfed). All larvae in the unfed group died by 15 DAH and the larvae in other experimental groups survived until the end of the experiment to 21 DAH. Survival rate was not significantly different between the 2 DAH group ($17.5{\pm}4.27%$) and the 3 DAH group ($20.5{\pm}1.5%$) at 21 DAH (P>0.05). However, there was a significant difference in survival rate between the 3 DAH group and the 4 DAH group ($11.7{\pm}1.52%$) (P<0.05). There was no significant difference in notochord length among the groups fed from 2 DAH, 3 DAH and 4 DAH at 21 DAH (P>0.05). The swimming ability in fed group gradually increased in both cruising and burst swimming speeds, while those abilities in unfed group gradually decreased after reaching the peak at 6 DAH in both cruise ($18.7{\pm}6.56mm/s$) and burst swimming speed ($43.5{\pm}12.65mm/s$).