Correlation between digestion rate and feeding frequency in the stomachless teleost, Blennius pholis L.

Abstract

Foregut emptying in Blennius pholis at 16–18°C is exponential (St=Soe‐Rt; R=0.006 when t is in min and s in mg dry weight). In consequence, the time for the foregut to empty completely varies in proportion to ln (meal size) in a chosen size of fish or to ln (body weight) in different sized fish fed to the same relative amount (% body weight). Appetite returns rapidly in comparison with other species (4–15 h for fish of 0.5−30 g) and, because of the tidal constraints imposed on this littoral fish, voluntarily ingested meals are large (14–9% body weight depending on fish size). Studies on digestion in small, stomachless fish are not adequately made using X‐radiography and must be supported by sequential gut samples after a meal.