SOME OBSERVATIONS OF THE EFFECTS OF BODY-WEIGHT, TEMPERATURE, MEAL SIZE AND QUALITY ON GASTRIC-EMPTYING TIME IN THE TURBOT, SCOPHTHALMUS-MAXIMUS (L) USING RADIOGRAPHY

The gastric emptying time (G.E.T.) in turbot was investigated using X‐radiography and was found to decrease with temperature. Small fish processed a given ration, expressed as percent body weight, faster than large fish (G.E.T. was found to be proportional to (fish weight)0.364). Large meals in a given fish were processed at a faster rate than small meals. Gastric emptying rate (G.E.R.) was found to be proportional to (meal size g)0.613 at 8° C and (meal size g)0.788 at 19° C. These exponents are in agreement with a recently proposed model relating G.E.T. and G.E.R. to meal size (Fänge & Grove, 1978). Large fish emptied a meal of given absolute size from the stomach at a faster rate (g h−1) than small fish. Experimental meals diluted with kaolin were evacuated in significantly less time than a control diet, suggesting that turbot may adjust feeding rates when food quality varies. Copyright © 1979, Wiley Blackwell. All rights reserved