Effects of different salinities on the growth, food intake and nutrient composition in underyearling masu salmon, Oncorhynchus masou (B.)
1992
Li, H.O. (Hokkaido Univ., Hakodate (Japan). Faculty of Fisheries) | Yamada, J.
The effects of different salinities on the growth, food intake, conversion efficiency, and body carbon and nitrogen contents were investigated by rearing fry and parr of masu salmon, Oncorhynchus masou (B.), with a commercial diet in fresh water (dechlorinated tap water, FW), 1/4 sea water (8+-1 0/00), 1/3 sea water (11+-1 0/00) and 1/2 sea water (15+=1 0/00). Weight gains in both fry (9 weeks) and parr (5 weeks) were significantly greater in FW than that in SW. However, no clear differences were observed among the SW groups. No significant differences in daily feeding rate were observed. The food conversion efficiency decreased significantly in the SW groups compared to the FW group. The body nitrogen content of fry after a 9 week rearing period was not different among the four groups, but the body carbon content was higher in the FW group than in the SW groups. Assimilations of carbon and nitrogen were not significantly different. The carbon assimilation efficiency in the 1/2 SW group, however, tended to be low compared to those in the FW and other SW groups
Показать больше [+] Меньше [-]