engleski

Nutritive value of alimentary tract comtents of rudd ( Scardinius erythrophtalmus L.) in the Vrana lake (Cres island-Croatia)

Rudd (Scardinius erythrophtalmus L.) belongs to the Cyprinidae family. Rudd fry start to be fed on zooplankton and continue with feeding on plants. Data on the nutritive value of their feed are scarce, so the aim of this paper was to determine the nutrition and nutritive value of different age groups feeding. Quality composition of the feed was determined by analysing guts content of 28 fish specimens belonging to age groups 1+ to 4+. The analysis showed the total number of 67 species of macro and microphytic algae belonging to the groups: Cyanophyta, Dynophyta, Chrysophyta and Chlorophyta which were represented in the total number as follows: Cyanophyta (8 species or 11.9%), Dynophyta (3 species or 4.5%), Chrysophyta (Bacillariophyceae, 36 species or 53.7%; Xanthophyceae, 1 species or 1.5%) and Chlorophyta (19 species or 28.4%). In all examined fish specimens microphythic algae of the group Bacillariophyceae were dominant in the feed. The nutritive value depended on proteins and lipids levels. The proteins level varied from 2.32% to 16.00%, and lipids level from 0.27% to 3.34%. The energetic value of guts content aried from 101.88 kJ to 252.30 kJ depending on the age group of the fish.

feeding;nutritional value;rudd (Scardinius erythrophtalmus L.)

nije evidentirano