Larval rearing and nursery production

Early tuna larvae have a very high number of free neuromasts on their body surface even higher than most pelagic species. These mechanorecep-tors make tuna larvae particularly sensitive to stress due to handling and transfer and may also result in stress caused by noise and vibration within 

Historically, feeding on Anemia nauplii has commenced between 10 and 13 dph and is continued until 25-28 dph (Kaji et al, 1996 Sawada et al, 2005 Masuma et al, 2008). However, as is described in greater detail below, there has been a recent shift away from such a prolonged use of Anemia based on aspects of their nutritional profile which appear inappropriate for tuna and which cannot be overcome through the typical enrichment processes. 

Although the use of Anemia in marine finfish larval rearing is almost ubiquitous, they are not a natural food source for any species and lack certain key nutrients required for the growth and development of marine fish larvae. The deficiency of Anemia in essential fatty acids has been long 

Whilst the importance of dietary inclusion of polar lipids is not unique to tuna and their benefits also widely demonstrated for many other species of marine fish larvae (Navarro, 1997 Cahu et al, 2003 Hadas, 2003 Gisbert, 

none has been shown to undergo the same growth failure experienced by tuna larvae when fed on enriched Anemia. The physiological mechanisms responsible for these differences have not been elucidated, but these findings reinforce that important differences exist between tuna larvae and those of other marine fish species. 

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