국립수산과학원 병리연구과, 1국립수산과학원 남동해수산연구소
Immunostimulating effects of fucoidan administration to rockfish Sebastes schlegelii at a concentration of 20 g/kg of diet were evaluated under high water temperature condition. The oral administration of fucoidan mixed with feed at a concentration of 20 g/kg of diet for 2 weeks increased the interleukin 1β gene in the intestine and kidney of fish by 5.7 and 6.3 times, respectively. In addition, when the water temperature was gradually increased from 24 to 31.4°C for 2 weeks, LT50 delayed by 24 hours in the fucoidan treated group compared to that in the control group, and mortality also reduced. Streptococcus iniae infection at a concentration of 1.50×100 CFU/fish at 28°C delayed LT50 by 12 h in the fucoidan-treated group. Furthermore, the overall survival rate was 0% in the control group and 20% in the fucoidan-treated group. This study confirmed the applicability of dietary additives such as fucoidan as an immune activator of rockfish under high temperature condition.
Sebastes schlegelii, Fucoidan, Streptococcus iniae, Immunostimulating, Water temperature