A study of effects of some factors on gastric emptying in brook trout (Salvelinus fontinalis Mitchill, 1814)

In this study, the emptying physiology of Brook Trout (Salvelinus fontinalis) was studied.The effect of temperature, fish size and food size were investigated. The emptying was best described by an exponential function.The different sizes of food (0,12gr., 0,36gr. and 0,18gr.) were used to have a look at the effect of food size. It was found that increases in food size increased the emptying rate, but decreased the gastric emptying time. This was found to be statistically important(P <0,01).In addition to the different sizes of fishes (114,84 + 9,2gr.; 49,06 + 8,5gr.) were used for investigate the effect of fish size. It was found that increases in fish size and increased the emptying rate, however; decreased the gastric emptying time. This was found to be statistically important(P <0,05).The effect of temperature (9,50C and 180C) was also tested. It was found that 2 fold increase in temperature, resulted 1,5 fold decreased in the gastric emptying time. this decrease was also found to be statistically important (P <0,01).Key Words: Brook Trout, Salvelinus fontinalis, Emptying physiology, Gastric emptying time and rate