Sediment-toxicity
Guides
Chironomus dilutus
Chironomus dilutus is a freshwater non-biting midge species in the family Chironomidae, described in 1999. The species has become a standard test organism in aquatic toxicology, particularly for chronic toxicity assessments of sediment-associated contaminants including pyrethroids, fluorotelomer acids, selenium, and microplastics. Laboratory studies demonstrate its sensitivity to various organic pollutants, with emergence and reproduction serving as key toxicological endpoints. The species is used in regulatory testing protocols for evaluating ecological risks of hydrophobic contaminants in freshwater systems.