Effect of trophic status and sediment particle size on diversity and abundance of aquatic Oligochaeta (Annelida) in neotropical reservoirs

Abstract

-The influence of the sediment grain size and the trophic status of the reservoirs on the composition, richness and biomass of Oligochaeta community was tested. Samples were taken from the littoral and profundal zones of 30 neotropical reservoirs from six different watersheds during two hydrological periods (dry and rainy seasons). The sample units were ordinated, with principal component analyses, according to differences in the sediment grain size, sample depth and dissolved oxygen. The results of a multiple response permutation procedure (MRPP) analysis revealed significant differences in species composition between littoral and profundal zones, trophic status (oligotrophic, mesotrophic and eutrophic) and different watersheds. The environment-species relationship was tested using redundancy analyses. In order to test which environmental variables, either granulometric or limnological, influenced the Oligochaeta community variability we used a partitioning procedure of inertia. Local variations, including reservoir zone and trophic status, were primarily influenced by differences in sediment type and depth. Significant differences in the total biomass between zones, trophic status, watershed and hydrological period were also demonstrated by a KruskalWallis or Mann-Whitney test. The most prevalent taxa were the cosmopolitan tubificids Bothrioneurum sp. and Branchiura sowerbyi, and the naidids Dero (Dero) digitata and Pristina breviseta, which are dependent on periphyton for food. Higher biomass values were recorded in mesotrophic reservoirs, due to increased nutrient availability and adequate dissolved oxygen supply. Our results indicate that the Oligochaete community structure is directly influenced by local environmental variation in neotropical reservoirs; and that the sediment grain size is the most important factor in determining the Oligochaete community structure.

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

“…Distribution: Paraná: Patos Lake and Ivinhema River (Montanholi-Martins & Takeda 2001); in the Paraná River (Montanholi- Martins & Takeda, 1999); in different floodplain habitats of the Paraná River , in several reservoirs in the state of Paraná (Moretto et al 2013); in the Paraná River, in the Ilha Grande National Park, between the states of Mato Grosso do Sul and Paraná (Ragonha et al 2013); in tributaries of the Paraná River ; in Ivinhema River and Baía River (Behrend et al 2009) and Iguaçu River (Behrend et al 2012). São Paulo: marginal lagoon of the Mogi-Guaçu River (Alves & Strixino 2000, 2003.…”

“…Distribution -São Paulo: Tietê River (Marcus 1942, 1943, Du Bois-Reymond Marcus, 1949a; in the Salto Grande eutrophic Reservoir (Dornfeld et al 2006); Americana Dam by Pamplin et al (2006); in the Monjolinho dam in the city of São Carlos (Fusari & Fonseca-Gessner 2006); Tietê River reservoirs by Pamplin et al (2005) and by Suriani et al (2007) and in a marginal lagoon of the Mogi-Guaçu River (Alves & Strixino 2000, 2003. Paraná: in several reservoirs in the state of Paraná (Moretto et al 2013) and in the Iguaçu River (Behrend et al 2012). Piauí: Poti River by Sales et al (2014).…”

“…In addition, these worms have limited mobility and are influenced by the habitat characteristics in which they are found (Behrend et al 2012). Thus, the richness and abundance of Oligochaeta is directly related to environmental variables (Marchese & Drago 1999, Jablonska, 2014, such as availability of food resources (Martins & Silveira, Alves 2011); dissolved oxygen (Dornfeld et al 2006); type of substrate (Moretto et al 2013); water temperature (Nascimento & Alves 2009), thus being considered indicators of specific habitats.…”

First record of Stephensoniana trivandrana Aiyer, 1926 (Oligochaeta: Naididae), in southeastern Brazil

“…The S. trivandrana specie belongs to family Naididae, sub family Naidinae (Timm, 2009). Until the present study, records of S. trivandrana, in Brazil, were limited to only three states: Mato Grosso (Marchese et al, 2005), Mato Grosso do Sul (Takeda et al, 2000) and Paraná (Montanholi-Martins and Takeda, 1999;Behrend et al 2009;Moretto et al, 2013). In previous studies in Southeastern Brazil, S. trivandrana had not yet been registered.…”

Oligochaeta (Annelida: Clitellata) associated to aquatic macrophytes in Brazil

“…According to other studies, this species is commonly found in regions rich in aquatic vegetation (DAVIS, 1982) and it is usually one of the most abundant species (CORREIA; TRIVINHO-STRIXINO, 1998;TRIVINHO-STRIXINO et al, 2000;. In turn, the species with lower prevalence, such as Brinkhurstia americana and Limnodrilus hoffmeisteri, are more adapted to live on sediment and the substratum composition and particle size was a major determinant of their distribution (MORETTO et al, 2013).…”