Production and Enrichment of Chironomid Larva with Different Levels of Vitamin C and Effects on Performance of Persian Sturgeon Larvae

Chironomid larvae have a high reproduction capacity. Because of their excellent nutritional quality, they have great potential in larval fish nutrition, specially bottom feeders like sturgeons. In this study, indoor production of Chironomus riparius was performed by controlling the physicochemical factors and developing an appropriate condition for this insect to complete the life cycle. Enrichment of lava was conducted by adding 0 (C-0), 100 (C-100), or 1000 (C-1000) mg of ascorbic acid to 1 kg of chicken manure (as substrate). Ascorbic acid analysis of chironomid larva showed significant differences among the groups: 74.2 mu g/g for C-0, 325.0 mu g/g for C-100, and 779.9 for C-1000. In the second experiment, enriched chironomids were fed to larval Persian Sturgeon Acipenser persicus and were compared with sturgeons fed live cladocerans, Daphnia, which are regulary used in hatcheries. Length and weight measurements after 14 d of the experimental period showed no significant differences in growth performance. Analysis of ascorbic acid in Persian Sturgeon viscera also showed no significant differences between the groups. In conclusion, chironomids could be cultured indoors and can be enriched to meet the nutritional requirements of fish. We found ascorbic acid did not have a signifucant effect on Persian Sturgeon larval feeding, but longer feeding periods and implication of unfavorable physicochemical conditions or causing stress tests might demonstrate the beneficial effects of this vitamin.