A comparison of improvemental ability of water quality among five chironomid species of the genus Chironomus

Abstract

Five chironomid species of the genus Chironomus were examined for caloric contents in adults and for their ability of calory removal from bodies of water by emergence and of water quality improvement in laboratory experiments. Calory per g adults was the highest (about 5,000 cal) for Chironomus kiiensis, higher than 2,500 cal for C. circumdatus, C. nippodorsalis and C. yoshimatsui and the lowest (about 2,000 call for C. nipponensis. The actual rate of removal by emergence was the highest (about 13%) for C. nippodorsalis, moderate (about 10%) for C. circumdatus and C. yoshimatsui, and the lowest (about 6%) for C. kiiensis and C. nipponensis. For inhibitory ability of eutrophication, in terms of PO_4-P concentration, about 89% of inhibition was observed for C. nipponensis. Inhibition was higher than 70% for C. circumadatus and C. yoshimatsui, about 31% for C. nippodorsalis, and the lowest (about 24%) for C. kiiensis at 4 weeks. For inhibitory ability in terms of protein concentration, inhibition was the highest (about 80%) for C. circumdatus, higher than 50% for C. kiiensis, C. nipponensis and C. yoshimatsui, and the lowest (about 41%) for C. nippodorsalis at 4 weeks.