• Title/Summary/Keyword: Oysters trochophore

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Seedling Production of Rabbitfish, Siganus canaliculatus (흰점독가시치, Siganus canaliculatus의 종묘생산)

  • Hwang, Hyung-Kyu;Lee, Jung-Uie;Rho, Sum;Yang, Sang-Geun;Kim, Seong-Cheol;Kim, Kyong-Min
    • Journal of Aquaculture
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    • v.13 no.4
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    • pp.277-284
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    • 2000
  • Rabbitfish hatchlings were given a mixed food of rotifers (Brachionus rotundiformis) and trochophore larvae of oyster. Only the oyster-trochophore larvae were found in the gut of 62-h old fish larvae. The fish larvae, fed on rotifer and ciliate alone did not survive. However, their survival increased to 3.3 % on the 10th day after hatching, when trochophore was supplemented. Corresponding with the accelerated growth, the number of rotifers consumed increased from 11 in a 5-day old fish to 165 in a IS-day old fish. In a field ecosystem containing live diatom, Nannochloropsis oculata, rotifers and copepods, fish larvae were shocked and the oyster's trochophore larvae were fed from 2 to 7 days after hatching. A total of 76,000 seedling were produced after 50 days of hatching with 12.7 % survival. Mean total length and body weight were 65.6 mm and 3.4 g, respectively. Growth of body length (BL), body height (BH), body weight (BW) and head length (HL) as a function of the total length (TL) showed regressional relationships as follows; BL=0.8565 TL+0.0852 ($t^2$=0.9996); BH=0.3207 TL - 0.5052 (($t^2$=0.9641) BW=0.0652 TL2.3508 (($t^2$=0.9925); HL=0.2595 TL - 0.1898 (($t^2$=0.9901)

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First observation on the early embryonic and larval development of spiny oyster Saccostrea kegaki Torigoe & Inaba, 1981 (Bivalvial: Ostreoida) using scanning electron microscope on the north coast of Jeju, Korea (주사전자현미경 (Scanning Electron Microscope)을 이용한 제주 북부 연안에 서식하는 가시굴 (Saccostrea kegaki Torigoe & Inaba, 1981)의 초기 유생발달관찰)

  • Lee, Hee-Jung;Kang, Hyun-Sil;Jeung, Hee-Do;Hong, Hyun-Ki;Choi, Kwang-Sik.
    • The Korean Journal of Malacology
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    • v.29 no.2
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    • pp.97-103
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    • 2013
  • In the present study, we monitored the early development of Saccostrea kegakia subtropical oyster species distributing on rocky intertidal off the northern Jeju Island using scanning electron microscope (SEM). The female oyster collected in early August, 2012 were fully mature exhibiting relatively small eggs ($46.5{\pm}1.4{\mu}m$ in diameter) in the gonad, while testis of the mature male oysters were filled with fully developed sperms of 36.9 ${\mu}m$ in length. The fertilized eggs developed into 2-cell stage with polar body after 1 hr 20 min of fertilization, then followed by Morula stage (3 hr 20 min), Blastula stage (4 hr 50 min), Gastrula stage (7 hr), and trochophore larvae stage (9 hr 30 min). The observed early development of S. kegaki in this study was similar the early development of other oysters, although size of the fertilized eggs were somewhat smaller.