@article{oai:kindai.repo.nii.ac.jp:00018399,
 author = {倉田, 道雄},
 issue = {15},
 journal = {近畿大学水産研究所報告, Bulletin of the Fisheries Laboratory of Kinki University},
 month = {Mar},
 note = {<Summary> Bluefin tuna aquaculture has been developed an economically important industry. Consequently, excessive demand of wild-caught tuna for seedling fish of the tuna aquaculture has resulted in over-fishing. Therefore, development of full-cycle bluefin tuna aquaculture methodology, which does not rely on natural resources, is necessary for sustainable tuna aquaculture. Recent attempts at developing Bluefin tuna fingerling production technology have been made in many countries. In Pacific bluefin tuna (PBT); however, the survival in fingerling production is still low. Although, the poor PBT survival is due to various cause, mass mortality by both larval surface death and sinking death during the early larval stage have been considered to be seriously affects PBT aquaculture operations. Especially, larval sinking death has been identified as a particularly serious problem causing mass mortality of PBT larviculture. Swimbladder inflation plays an important role in controlling larval body density and their buoyancy. On the other hand, PBT larval body density is greater than that of rearing sea water, even when larvae possess an inflated swimbladder, and is believed to be the primary cause of sinking death particularly during the night-time on ceasing swimming (Takashi et al. 2006). Therefore, larval swimbladder inflation and flow control of rearing water during the nighttime to suspend larvae within the rearing water column have the possibility to improve larval sinking death in PBT larviculture. However, the definite relationships between swimbladder inflation failure and survival have not yet been investigated in PBT not to mention the effective promotional method of initial swimbladder inflation (ISI). In addition, the flow control in rearing tanks has also not yet been examined in detail its enhancement effect of survival in larviculture. Furthermore, regarding the swimbladder, its inflation failure induces poor growth and vertebral deformity, and it often negatively affects the production efficiency in other aquaculture fish species. However, the definite relationships between swimbladder inflation failure and growth, vertebral deformity have not yet been elucidated in PBT. The purpose of this study is to improve PBT fingerling production technology. Firstly, in Chapter 1, the effects of different air supply rate during the nighttime on larval survival and water circulation of rearing tank were evaluated, and larval sinking velocity was also determined to improve larval mortality due to sinking death.In Chapter 2, the influence of ISI failure on larval vertical distribution and survival were investigated. In Chapter 3, the promotional and inhibitory conditions of water surface for ISI and the optimal timing for ISI promotion were investigated to develop the suitable ISI promotion method; additionally, the relationship between ISI promotion and occurrence of surface death was also investigated. In Chapter 4, influence of swimbladder inflation failure on mortality, growth and lordotic deformity in postflexion larvae and juveniles were investigated to obtain the information for the improvement of fingerling production technology in PBT., application/pdf},
 pages = {1--141},
 title = {Study on prevention of sinking death in the fingerling production of Pacific bluefin tuna},
 year = {2015},
 yomi = {クラタ, ミチオ}
}