Does Type of Substratum Affects Chironomid Larvae Assemblage Composition? A Study in a River Catchment in Northern Patagonia, Argentina

详细信息    查看全文

• 作者：M Mauad ; A Siri ; M Donato
• 关键词：Chironomidae ; habitat preference ; altitudinal zonation ; South America
• 刊名：Neotropical Entomology
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：46
• 期：1
• 页码：18-28
• 全文大小：
• 刊物主题：Entomology; Agriculture; Life Sciences, general;
• 出版者：Springer US
• ISSN：1678-8052
• 卷排序：46

文摘

Chironomid larvae assemblages were investigated at seven sampling stations in relation to stream habitat type in the Challhuaco-Ñireco river system located in the Nahuel Huapi National Park, in the North-Western part of Rio Negro Province, Argentina. A total of 2229 individuals were sampled and 43 Chironomidae taxa were recorded with Orthocladiinae (29) being the best represented subfamily, followed by Diamesinae (5), Tanypodinae (3), Podonominae (3) and Chironominae (3). Stictocladius spF, Cricotopus (Paratrichocladius) sp6, Cricotopus sp2, Cricotopus sp3 and Parapsectrocladius sp2 were the most abundant taxa. Sites near the source of the river system were dominated by Podonomus sp., Limnophyes sp., Parapsectrocladius sp. and Stictocladius spF, whereas sites close to the river mouth were dominated by Diamesinae sp5 and Cricotopus sp. Rank/abundance plots show that all the analysed sites displayed dominance of some species. Stictocladius spF, Cricotopus sp2, Cricotopus sp3, Cricotopus (Paratrichocladius) sp6, Parapsectrocladius sp. and Limnophyes sp. resulted as dominant species, or being part of a group of dominant species, at least in one sample. Eleven taxa were associated with habitats related with riffle areas and stable substrates with filamentous algae. Species–environment relationships were examined using ordination analysis. Elevation was the most significant environmental variable that explained 22% of the total variability of the chironomid assemblages, showing stronger relationships among sites within an altitudinal gradient than among habitat type. Abundance of chironomids increased from headwaters to the outflow in Nahuel Huapi Lake responding to an altitude gradient as well as some environmental factors such as coarse matter and nutrient concentrations.