Efficacy of high water temperature treatment against Pseudodactylogyrus spp. infection in Japanese eel [Anguilla japonica]
2009
Tanaka, M.(Shizuoka-ken. Research Inst. of Fishery, Hamamatsu (Japan). Hamanako Branch) | Satoh, T. | Matsuyama, H.
We investigated seasonal changes in the abundance of Pseudodactylogyrus spp. (Pd) in Japanese eel Anguilla japonica in culture ponds. For this purpose, the number of parasite eggs floating in the rearing water was counted as an indicator. In spring, the average number of floating eggs was 40.3 (SD = 53.2) per liter of rearing water, which was maintained at 28-30degC by heating. In summer, the water temperature increased up to 30degC or higher without heating. During this period, the number of floating eggs was high at 30degC and was low at = 32degC. The number of floating eggs was the highest (maximum number of eggs, 1,678 per liter) in autumn when the temperature ranged from 23degC to 30degC. In winter, the number of eggs was again low. On the basis of these results, we reared eels infected with Pd in fresh water at 29degC, 32degC and 35degC for 20 days to control this parasitic disease. Parasites did not decrease in number at 29degC, but clearly decreased at 32degC, and almost disappeared at 35degC within 5 days. When heavily infected eels were maintained at 35degC for 5 days in a greenhouse pond, mortality due to the infection clearly decreased.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by Agriculture, Forestry and Fisheries Research Information Technology Center