مطالعه ارتباط بين تغييرات دماي نگهداري ماهيان قزل آلاي رنگين كمان در بروز تومور كبد (هپاتوما)

Study of relation between the temperature changes and hepatoma incidence in Rainbow trout

One of important problems in cold water fish culture is hepatoma (liver tumor) incidence arising of feed aflatoxins specially aflatoxin Bl. This research surveid relation between of culture temperature and hepatoma incidence rate. Rainbow trout (initial weight 4-6 gram) were acclimated at cool 9-10 degrees C a intermediate temperature 14-15 degrees C or an warm temperature 17-18 degrees C for 45 days. Fish were exposed to 0.1 ppm of waterborne aflatoxin B1 for 40 min at respective acclimation temperature and reared for 200 days at cold - intermediate or warm temperatures. Incidence rate of hepatoma were 7%-39% and 59% respectively ( cold temperature group- intermediated temperature group and warm temperature group). The average number of tumor per fish liver increased from 100% at cold temperature group . There were no temperature- dependent differences in tumor size. With this result suggested temperature increase was promoter for hepatoma tumor growth in rainbow trout.