The effects of heavy metals on the incidence of morphological deformities in Chironomidae (Diptera)

By

Deliberalli, Wanesssa
Cansian, Rogerio L.
Mielniczki Pereira, Albanin A.
Loureiro, Rafael Chaves
Hepp, Luiz Ubiratan
Restello, Rozane M.

Type

Article

Date of Publication

2018-4-23

Original Publication

MycoKeys

Volume

35

Pages

1--7

Subjects

biomonitoring , Copper , Environmental quality , mentum , Zinc

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers 2011-

Identifiers

DOI: https://doi.org/10.3897/zoologia.35.e12947

 

Abstract

Streams in urban areas are strongly impacted by the input of organic matter and metals, for instance copper (Cu) and zinc (Zn). These metals are essential for the aquatic biota, but when absorbed in excess they are toxic. In Chironomidae larvae, the deleterious effects of heavy metals can be ascertained by analyzing the morphological deformities of the larval mentum, a structure of the oral cavity. In this study, we evaluated I) the bioavailability of Cu and Zn in urban stream sediments and II) the relationship between Cu and Zn concentrations and the incidence of deformities in the mentum of Chironomus larvae. Chironomid flies were collected from four locations in two streams at an urban area in southern Brazil. They were identified and the incidence of deformities in the mentum was quantified. Sediment samples were collected at the same locations where larvae were collected, to quantify the bioavailable fractions of Cu and Zn. The concentrations of Cu in the sediment were similar between the collection sites. However, Zn concentrations varied among sites, being greater in the stretch directly influenced by the input of the organic waste. In total, 2,895 Chironomid larvae were collected. The incidence of deformities in the mentum was above 30% and was correlated with the concentrations of Cu (r = 0.68) and Zn (r = 0.87). This correlation indicates that the municipal waste that is thrown into the city’s streams has influenced the occurrence of deformities.