Oligochaetes (Annelida, Clitellata) in a neotropical stream: a mesohabitat approach

Guilherme R Gorni,Roberto Da G Alves

doi:10.1590/s0073-47212012000100015

Guilherme R Gorni, Roberto Da G Alves

Open Access

https://doi.org/10.1590/s0073-47212012000100015

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Abstract

This paper analyses the relationship among mesohabitat and aquatic oligochaete species in the Galharada Stream (Campos do Jordão State Park, state of São Paulo, Brazil). Between August 2005 and May 2006 a total of 192 samples were obtained in areas of four different mesohabitats: riffle leaf litter (RL), pool leaf litter (PL), pool sediment (PS) and interstitial sediment from rocky beds in riffle areas (IS). In the mesohabitats sampled, 2007 specimens were identified, belonging to two families (Naididae and Enchytraeidae). Among the oligochaetes identified Naididae was represented by six genera (Allonais, Chaetogaster, Nais, Pristina, Aulodrilus and Limnodrilus). Principal components analysis (PCA) revealed the first two axes explained 85.1% of the total variance of the data. Limnodrilus hoffmeisteri Claparede, 1862 and Aulodrilus limnobius Bretscher, 1899 were associated with the pool areas (PL and PS). Most species of genera Pristina and Nais demonstrated apparent affinity with the riffle mesohabitats. The Indicator Species Analysis (IndVal) revealed that Nais communis Piguet, 1906, Pristina leidyi Smith, 1896 and Pristina (Pristinella) jenkinae (Stephenson, 1931) are indicative of RL mesohabitat, while family Enchytraeidae was considered indicative of PL mesohabitat.

Highlights

According to Pardo & Armitage (1997), the types of substrate and flow pattern result in a mosaic distribution of species in mesohabitats, each inhabited by particular assemblages of indicator species
Majority of the oligochaetes considered as indicators prefer specific habitats and the occurrence of these habitats depends on a complex interaction between different substrate types and water flow patterns (Verdonschot, 2001)
According to Beisel et al (1998), the species richness increases with the heterogeneity of the habitat and the total abundance rises with the food availability, while the diversity of species tend to increase with the stability of the substrate

Summary

Introduction

Studies of the spatial distribution of oligochaete species have shown that these invertebrates respond to the nature of the substrate and the water flow conditions (Stacey & Coates, 1996; Verdonschot, 1999, 2001; Alves et al, 2006; Schenková & Helešic, 2006, among others). This contribution analyses the relationship among mesohabitat and aquatic oligochaetes species in the Galharada Stream, located in Campos do Jordão State Park in the state of São Paulo, Brazil.

Results

Conclusion