Molecular identification of Chironomus spp. (Diptera) for biomonitoring of aquatic ecosystems

Abstract   Chironomidae larvae often represent a major component of the benthic fauna in inland water bodies and are used frequently as bioindicators of ecosystem health. The genus Chironomus is a recognised indicator of organic enrichment and has been used extensively in the northern hemisphere and New Zealand in ecotoxicological studies. However, similar use of Chironomus in Australia is limited due to the presence of cryptic species that restrict the collection of information on species-specific responses to environmental stress. To address the problems associated with species identification, we have used PCR-RFLP of the mitochondrial COI gene to develop DNA profiles for nine common Australian Chironomus species. Species-specific haplotypes were identified using reference taxa previously identified by cytological analysis, and verified with field specimens collected from seven wetlands around Melbourne. This research provides an effective tool for species identification of this ubiquitous and often abundant genus that will provide the basis of obtaining species-specific information to inform on the health of aquatic ecosystems.