Function of Ventral and Lateral Processes in Larvae of Chironomus (Diptera, Chironomidae)

Oxygen consumption by larvae of five Chironomus species from the Plumosus group belonging to different larval forms was studied. Larvae of C. agilis ( f. l. reductus) were unable to utilize oxygen at its concentrations lower than 1 mg/l. Larvae of C. plumosus ( f. l. plumosus) used oxygen from water at concentrations higher than 0.7 mg/l; pupas of this species and larvae of C. borokensis ( f. l. plumosus) utilized oxygen at concentrations lower than 0.4 mg/l. C. entis and C. muratensis (both-- f. l. semireductus) utilized oxygen from water at its concentrations up to 0.05 mg/l. The lack of correlation between the rate and ability of larvae to use oxygen at low concentrations and the degree of development of processes allows suggesting that these structures are not additional respiratory organs, as is commonly accepted. At the same time, ability of species to inhabit under conditions of oxygen deficiency correlates directly with the size of the processes. Therefore, ventral and lateral processes are suggested to perform a function of excretion of anaerobic metabolism metabolites.