Feeding Behavior of the Ruffe Gymnocephalus cernuus Triggered by Olfactory and Gustatory Stimulants

摘要

The feeding behavior of the ruffe Gymnocephalus cernuus mediated by olfactory and gustatory stimulants was studied. It was found that natural olfactory food stimulants (extract solutions of food organisms) cause a poorly pronounced attraction and foodsearch only at high concentrations (10~(-2)-10~(-1) g/l). Solutions of tree amino acids--alanine, glycine. proline, glutamine. and glutamic acid (10~(-4) M)are inefficient and only trip-lophane solution (10~(-4) M) stimulates a weak food response. It was established that the behavioral gustatory response in the ruffe is more complex than in many other fish species studied earlier. With reference to the ruffe, the existence of new kinds of gustatory substances (arousants) stimulating repeated fish contacts with food items for a more strict preliminary assessment of correspondence to the food demands of feeding fish apparently using external gustatory receptors was shown for the first time. Only some of these substances (alanine and eysteine. 10~(-1) M)increased the frequency of seizing artificial food pellets. Among four classic taste substances and eight free amino acids used, no gustatory stimulants increasing pellet consumption were revealed. Only extract of Chironomidae larvae (75 g/l) had such an effect. The role of olfactory and gustatory systems in the sensory support of the feeding behavior of the ruffe is discussed.