Record of Haplotaxis aedeochaeta Brinkhurst & Marchese, 1987 (Oligochaeta: Haplotaxidae) in a conservation unity in the state of São Paulo

Oligochaeta is a diversified, widely distributed group that inhabits terrestrial, marine and freshwater environments (Timm, 2017). In continental aquatic ecosystems, it is composed of more than 1.100 known species (Martin et al., 2008), which play an important role in the decomposition process as most species are detritivorous (Rodriguez and Reynoldson, 2011). These organisms can be found in several microhabitats in aquatic environments, living in sediment or in water columns (Rodriguez and Reynoldson, 2011) and in association with other organisms (Corbi et al., 2004, 2005; Gorni and Alves, 2007; Martins and Alves, 2008; Oda et al., 2015). In addition, they have limited mobility and are influenced by habitat characteristics (Behrend et al., 2012), which make them efficient bioindicators of water quality. However, despite the growing number of research projects focused on oligofauna in Brazil (Rosa et al., 2015; Sanches et al., 2016; Takeda et al., 2017), few regions have an inventory, thus explaining the need to intensify research throughout the country. In this scenario, the Southeast and South regions, represented mainly by the states of São Paulo, Minas Gerais and Paraná, are among those with the greatest amount of research performed (Rodrigues and Alves, 2018). In this note, we report the record of the species Haplotaxis aedeochaeta in aquatic systems in a conservation unity in the state of São Paulo. The samples were collected in Ribeirão Bonito river at “Morro do Diabo” State Park in 2015 (22°30’12” S and 52°21’30” W) by the Environmental Company of the state of São Paulo (CETESB) following methodological procedures of the Technical Standard CETESB L5.309 (CETESB, 2003). We used the taxonomic criteria adopted by Brinkurst and Marchese (1989) in the oligochaetes identification. According to Brinkurst and Marchese (1987, 1989), this species is characterized as being long and thin, similar to a line and by a ventral chaetae single, longer and nodulate with curved distal end (Figure 1). The dorsal chaetae, when present, is short and

(With 1 figure) Oligochaeta is a diversified, widely distributed group that inhabits terrestrial, marine and freshwater environments (Timm, 2017). In continental aquatic ecosystems, it is composed of more than 1.100 known species (Martin et al., 2008), which play an important role in the decomposition process as most species are detritivorous (Rodriguez and Reynoldson, 2011). These organisms can be found in several microhabitats in aquatic environments, living in sediment or in water columns (Rodriguez and Reynoldson, 2011) and in association with other organisms (Corbi et al., 2004(Corbi et al., , 2005Gorni and Alves, 2007;Martins and Alves, 2008;Oda et al., 2015). In addition, they have limited mobility and are influenced by habitat characteristics (Behrend et al., 2012), which make them efficient bioindicators of water quality.
However, despite the growing number of research projects focused on oligofauna in Brazil (Rosa et al., 2015;Sanches et al., 2016;Takeda et al., 2017), few regions have an inventory, thus explaining the need to intensify research throughout the country. In this scenario, the Southeast and South regions, represented mainly by the states of São Paulo, Minas Gerais and Paraná, are among those with the greatest amount of research performed (Rodrigues and Alves, 2018).
In this note, we report the record of the species Haplotaxis aedeochaeta in aquatic systems in a conservation unity in the state of São Paulo. The samples were collected in Ribeirão Bonito river at "Morro do Diabo" State Park in 2015 (22°30'12" S and 52°21'30" W) by the Environmental Company of the state of São Paulo (CETESB) following methodological procedures of the Technical Standard -CETESB L5.309 (CETESB, 2003). We used the taxonomic criteria adopted by Brinkurst and Marchese (1989) in the oligochaetes identification. According to Brinkurst andMarchese (1987, 1989), this species is characterized as being long and thin, similar to a line and by a ventral chaetae single, longer and nodulate with curved distal end ( Figure 1). The dorsal chaetae, when present, is short and straight. The prostomium is large and divided by a groove, but without proboscis. The genital chaetae is large, similar to a capillary and occurs in segment XII.
In Brazil, Haplotaxis aedeochaeta had registered occurrence in the state of Paraná (Behrend et al., 2009;Takeda 1999, 2001;Petsch et al., 2015;, mainly in the Paraná River and its tributaries. Recently, it was evidenced in the state of Mato Grosso by Gorni et al. (2018) on Juruena River and Mato Grosso do Sul by Takeda et al. (2017) in the Ivinhema River region. In São Paulo, the species has already been collected by Oliveira (2009) on the Araquá River in the municipality of Botucatu in an area with few riparian forest and great influence of agribusiness. In other countries of South America, it occurs only in Argentina (Christoffersen, 2007).
The present research increases the data on the occurrence of H. aedeochaeta. This fact shows the importance of elaborating inventories for Brazilian aquatic ecosystems in order to reduce the gaps in data on neotropical biodiversity and highlight the importance of these organisms to the scientific community, also making possible their use in environmental monitoring research as bioindicators.