Induction of Deformities of the Hard-Chitinized Mouthpart Structures of Larvae Chironomus riparius Meigen under Various Contents of Persistent Organic Substances in Bottom Sediments

Abstract

It is shown that the number of deformations of mouthpart structures of larvae Chironomus riparius reflects the potential danger of contaminated bottom sediments and can serve as a good biomarker when monitoring the ecological status of freshwater ecosystems. The method of quantification of the deformation rate of hard-chitinized structures (mentum and mandibles) has been approbated. It has been revealed that the total amount of polychlorinated biphenyls in bottom sediments affects the portion of larvae with multiple deformations and the relative number of larvae with deformations of mentum and mandibles. Examples of calculating the index of the morphological response of hard-chitinized mouthpart structures of chironomid larvae exposed to bottom sediments with various contents of persistent organic substances are given.