author(s)
Naira Mohamed Lotfi, Rowaida Saleh Ahmed, Sahar Ahmed El-Shatoury and Amro Hanora

abstract
Mouthparts deformations in the larvae of chironomus sp. are well recognized indicators of the environmental degradation. The natural incidence of morphological abnormalities in the chironomid larvae was investigated in the present study. Three sites at Lake Manzala Egypt, were chosen to cover the southern sector of the lake that is reportedly, characterized by industrial, agricultural and domestic pollution. Chironomus transvaalensis was the dominant species showing distinct deformation features with 92% of all the scanned specimens reported as deformed. Even though, elevated concentrations of heavy metals were detected in the water, sediment and larval tissue samples, the high rate of deformation could not be solely explained on the basis of one type of water pollution, this suggests that there is uninvestigated synergism of several stressors. The miscellaneous sources of pollution in the lake further support this conclusion. Applicable in situ, the environmentally inflected deformities in Chironomus transvaalensis mouthparts warrant further investigation, subsequently stressing their role as effective bioindicators to assess stressed aquatic ecosystems.