Thermal tolerance of a rainbow trout Oncorhynchus mykiss strain selected by high-temperature breeding
Article first published online: 5 AUG 2005
Volume 71, Issue 4, pages 767–775, August 2005
How to Cite
INENO, T., TSUCHIDA, S., KANDA, M. and WATABE, S. (2005), Thermal tolerance of a rainbow trout Oncorhynchus mykiss strain selected by high-temperature breeding. Fisheries Science, 71: 767–775. doi: 10.1111/j.1444-2906.2005.01026.x
- Issue published online: 5 AUG 2005
- Article first published online: 5 AUG 2005
- Received 7 June 2004. Accepted 4 February 2005.
- embryonic development;
- high temperature breeding;
- upper 50% lethal temperatures;
- Oncorhynchus mykiss;
- rainbow trout;
- thermal tolerance
ABSTRACT: Thermal tolerance was studied in a rainbow trout strain successively selected through high temperature breeding at 20–27°C since 1966 in Miyazaki Prefecture, Japan. The hatching rate and fry mortality at high temperatures were examined in the selected strain along with normal strains cultured at water temperature of 9–17°C. The hatching rate of embryos fertilized at either 10 or 14°C and subsequently subjected to high temperatures in the blastula or neurula stage of the selected strain, was marginally higher than that of the normal strain counterparts. The upper 50% lethal temperatures (LT50) for embryos in the early segmentation, blastula and neurula stages of the selected strain were also higher than those of the normal strain counterparts. Death temperatures and LT50 of fries acclimated to 20°C of the selected strain were significantly higher than those of the normal strains. However, no difference in the critical thermal maximum was detected between the different strains. These results suggest that the selected strain of rainbow trout established by selecting successively for many generations at high temperatures acquired a degree of thermal tolerance.