Abstract
The aim of the study was to determine how natural feed supplemented with dry diets affects the growth rates and survival of larval asp, Aspius aspius (L.), and nase, Chondrostoma nasus (L.). The fish were reared for 21 days. Initially, the larvae were fed live Artemia sp. napulii, and a commercial feed SGP 493 (Aller Aqua) was added after 6 (A6), 8 (A8), 10 (A10), and 12 (A12) days. Depending on the feeding treatment, dietary supplements were then added to the natural feed at intervals of 1, 2, or 3 days. No statistically significant differences were noted in the growth of larval asp from groups A6 or A12, and groups A8 or A10. The relative growth rates (RGR) ranged from 18.16 (A8) to 18.61% d-1 (A12). No statistically significant differences were noted among the experimental groups of larval nase. RGR values ranged from 12.74 (A6) to 12.91% d-1 (A12). The results obtained indicate that supplementing with dry diets, which was done as early as in the first week of larval exogenous feeding, has a positive influence on the fish. This indicates that greater flexibility in feeding can be applied during the initial rearing of the larval stages of the species tested.