Chironomus aprilinus PRODUCTION IN UNDERGROUND BRACKISH WATERS, IRAN
Chironomus aprilinus Meigen, 1830 is endemic blood worm in sediments of the earthponds of Bafq area at center of Iran. Mean of chironomid larvae frequencies in sediments of the enriched earthpond was 8800±2690/m2 maximally in winter. Collection of egg masses was performed by innovative collectors prepared with low cost materials. May, June and July were the best time for egg collection. Culture of blood worms was successful in glass thanks with 16h. light, at 24-26°C temperature. Blood worms were withdrawn 14 days after egg incubation. Suitable concentration of harvesting is 1250eggs/m2 (1-2 egg masses/m2) leads to 89% hatching. Enrichment of earthponds or plastis thanks including sediment is offered for culture of chironomid larvae. Large blood worms were mainly available in winter. Results of body analysis of the larvae indicated high dry matter with good quality.
Chironomidae is a large family of the order Diptera including nonbitting midges. Larval stage of chironomids called as blood worms are valuable for feeding of some cultured aquatics as a live food. Blood worms form high percents of food items of some aquatics in natural habitats (Pearson and Peters, 2000). Body analysis of blood worms has shown valuable composition for feeding aquatics especially as a source of iron (Yashouv, 1956). Fish fries supplied with blood worms has higher body size, growth rate, survival and stocking success (Volkman et al., 2004).
Investigations on importance of blood worms in aquatic nutrition in Iran (Ghezel, 1993; Abedian Kenari, 2005) and chironomid larvae culture (Sahragard and Rafatifard, 2006 and 2010) is limited to some recent studies. Fish culture in underground brackish water earthponds of Bafq area at south east of the province is the main portion of the yearly production. An investigation on limnology of earthponds of Bafq area (Mashaii, 2006) revealed chironomid larvae as the dominant macrobenthics. Taxonomic studies on chironomid midges and macrobenthic larvae indicated that Chironomus aprilinus is the dominant species of the area (Rajabipour, 2008).
This study engages in breeding of chironomid midges, C. aprilinus in capture, incubation of their eggs and their culture under the condition of the incubators and earthpond.