Oligochaeta (Annelida: Clitellata) in the Juruena River, MT, Brazil: species indicators of substrate types

Abstract

Oligochaeta assemblages are important components in freshwater environments, where their abundance and composition may indicate aspects related to water quality and sediment. The lack of information about these communities in Brazilian aquatic environments, as well as the application of native species as bioindicators of lotic environmental, stimulated the conception of this paper. Thus, the aim was to study the community of aquatic Oligochaeta in selected stretches of the Juruena River (MT), thereby generating grounds for future environmental monitoring action in lotic ecosystems. For this purpose, samples were analyzed at bimonthly intervals during the period from January to November 2009, in stretches of the Juruena River (Amazon River Basin) located in the State of Mato Grosso (MT). Two methods were used to collect the organisms: a) "D" network in small clusters of fixed macrophytes in the sediment on the river banks; and b) Ekman-Birge dredge in fine sediment. Preliminary results were 584 organisms distributed in 22 taxa. Of these, 22 valid species were identified. This number corresponds to approximately 25% of the aquatic oligochaete species registered in Brazil. Of these species, Limnodrilus hoffmeisteri, Dero nivea and Pristina rosea can be associated with organic enrichment conditions and/or some level of environmental degradation.

Effects of fish cage culture on macrobenthic communities in a subtropical river

“…The present results were consistent with Hossain et al (2009) that also found higher number (53.75%) of Oligochaeta in Meghna river estuary. Oligochaeta assemblages to be important components in freshwater environments (Gorni et al 2018); these organisms are found in almost all freshwater aquatic environments (Cesar and Henry 2017), and are the most abundant groups in freshwater ecosystems (Ragonha and Takeda 2014; Cesar and Henry 2017). Therefore, having observed more Oligochaeta in freshwater ecosystems in the present study was considered common.…”

Trophic ecology of detritivorous fish along a reservoir cascade in a tropical semi‐arid region

“…These characteristics alter trophic conditions, generating a more homogenised environment that provides a greater supply of organic detritus . This would also explain the high intake of protozoa and oligochaetes by the species because they are bioindicators of pollutants in the aquatic environment (Lima, Grazziotti & Silva, 2018;Gorni, Sanches, Colombo-Corbi & Corbi, 2018). algae, periphyton, invertebrate and plant remains are present (Fugi et al, 2001;Neto et al, 2007;Vari, 2003).…”

Aquatic oligochaetes (Annelida: Clitellata) in reservoirs in São Paulo State: list of occurrence and ecological observations on the species

“…The L. hoffmeisteri species has hemoglobin, which enables them to support low oxygen concentrations (ESTEVES, 1998), and is therefore characterized as an indicator of organically polluted environments (VERDONSCHOT, 1989;PASTERIS et al, 1999;SURIANI et al, 2007;BEHREND et al, 2012;ZHAO;LIU, 2012;ZEYBEK et al, 2018;GORNI et al, 2018;GIROLLI, 2019). Record and ecological observations: Until now there was no record of occurrence of this species in Brazil, its occurrence was recorded only in Venezuela and Europe (CHRISTOFFERSEN, 2007).…”