EFFECTS OF TEMPERATURE ON THE FOOD-PROCESSING OF 3 SPECIES OF SEAWEED-EATING FISHES FROM EUROPEAN COASTAL WATERS

Food consumption, gut transit times and assimilation efficiencies of the temperate fishes Lipophrys pholis and Parablennius sanguinolentus (Blenniidae) and Gobius cobitis (Gobiidae. when fed the green alga Ulva lactuca were determined at four temperatures in the laboratory. Food consumption increased and gut transit times decreased with increase in temperature in all three species. Assimilation efficiencies for algal carbon and nitrogen did not vary with temperature in G. cobitis. Carbon but not nitrogen assimilation efficiency varied with temperature in P. sanguinolentus, and both carbon and nitrogen assimilation efficiencies changed broadly with temperature in L. pholis, the most omnivorous of the three fishes. Assimilation efficiencies of all three species were generally within the previously reported ranges for herbivorous marine fishes. These species are thus clearly capable of extracting energy from algal food sources. Copyright © 1990, Wiley Blackwell. All rights reserved