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Yutaka Haga Toshihito Naiki Youhei Tazaki Takaaki Shirai Yusuke Takaki Yosuke Tanaka Kazunori Kumon Satoshi Shiozawa Shukei Masuma Toshihiro Nakamura Shuzo Ishida Toshio Takeuchi 《Fisheries Science》2011,77(2):245-253
Two feeding experiments were conducted to determine the effect of a 5′-inosine monophosphate (IMP)-supplemented casein peptide-based microdiet (MD) on the feeding activity, growth and survival of Pacific bluefin tuna (PBT) larvae. PBT larvae [total length: 14.0 mm (Exp. 1) or 13.3 mm (Exp. 2)] were fed a casein peptide-based MD supplemented with or without 3% IMP for 12 days. As a negative control, a limited number of yolk-sac larvae of spangled emperor Lethrinus nebulosus were fed only for the first 7 days and starved for the next 5 days. A sufficient amount of yolk-sac larvae of spangled emperor was fed in the Exp. 2. All fish in the control group had died by 9 or 10 days after the experiment. Extensive mortality was observed in fish fed the MD. The MD was only found in the stomach contents of PBT fed the MD + IMP. Of the fish fed an IMP-supplemented diet, 50% survived for 12 days after the initiation of both feeding experiments. In addition, significantly higher growth than that observed during the first 7 days was seen in the PBT in the IMP treatment after 12 days of the feeding experiment. These results suggest that the supplementation of casein peptide-based MD with IMP could improve the feeding activity, survival and growth performance of PBT. 相似文献
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Aoki Ryuichiro Chuda Hisashi Washio Youhei Masuma Shukei Kato Keitaro 《Fisheries Science》2020,86(1):57-64
Fisheries Science - The aquaculture of greater amberjack Seriola dumerili is of considerable research interest worldwide. The larviculture methods employed to culture this species, however, are... 相似文献
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Yoshiki Kato Takayuki Takebe Shukei Masuma Takashi Kitagawa Shingo Kimura 《Fisheries Science》2008,74(1):48-53
ABSTRACT: Physical conditions such as oceanic turbulence related to food availability are considered to be important factors affecting fish larval survival. Rearing experiments were conducted to elucidate the effects of turbulence on the survival and feeding rates during the initial feeding period of Pacific bluefin tuna Thunnus orientalis . Six levels of turbulence intensity were provided by changing flow rates from pipes set on the bottom of rearing tanks. The result showed a dome-shaped relationship between turbulence level and survival rate, in which the feeding rate appeared higher at a logged turbulence energy dissipation rate of −6.32, and decreased at both higher and lower turbulence levels. Compared with the turbulence intensity in the ocean, the optimal turbulence level for Pacific bluefin tuna larvae corresponded to the turbulence caused by sea surface winds with speeds of 4–12.5 m/s. The estimated optimal turbulence intensity for Pacific bluefin tuna larvae is comparable to that for yellowfin tuna Thunnus albacares . 相似文献
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Shukei Masuma Gunzo Kawamura Nobuhiro Tezuka Masahiko Koiso Kenji Namba 《Fisheries Science》2001,67(2):228-231
SUMMARY: In bluefin tuna culture, a high mortality of juveniles is caused by bumping into the tank and net-pen walls at dawn. This bumping can possibly be attributed to visually disoriented behavior of the fish. To examine this possibility, the authors carried out retinomotor response experiments with juvenile bluefin tuna (50.7–96.8 mm total length, at which they were transferred from a indoor tank to a sea net-pen) and measured ambient light intensity at the culture site at dawn. The light intensity at which the transition from scotopic to photopic vision takes place was 7.52 lx and the time taken by the transition was 15 min. At dawn, the ambient light intensity rapidly increased from scotopic light intensity level and attained photopic light intensity level in 10 min. This incompatibility of the retinal adaptation with the change in the ambient light intensity could cause the visual disorientation of the fish. It is therefore possible that the visually disoriented juveniles cannot control their high power swimming and thus bump into the walls at dawn. 相似文献
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Takayuki Takebe Takeo Kurihara Nobuaki Suzuki Kentaro Ide Hideki Nikaido Yosuke Tanaka Satoshi Shiozawa Hitoshi Imaizumi Shukei Masuma Yoshitaka Sakakura 《Fisheries Science》2012,78(2):343-350
We conducted a rearing experiment on Pacific bluefin tuna (PBT) larvae, which originated from one female broodstock, and determined
the growth history of the larvae to clarify when the growth difference occurs. We investigated the otolith microstructure
of the PBT larvae to examine the individual growth history and to predict the age and body size at the onset of individual
growth difference. Since total length (TL) of fish can be back-calculated from otolith radius, we back-calculated TLs of 100
fish of 19 days post hatch (dph) divided into three size groups (small, intermediate, large). Growth difference was recognized
from 3 dph (mouth opening), and the difference became larger thereafter. Growth of large-size fish was assumed to be promoted
by the feeding conditions of PBT larvae. 相似文献
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