<b>Testate amoebae (Protozoa Rhizopoda) in two biotopes of Ubatiba stream, Maricá, Rio de Janeiro State

Abstract

ABSTRACT. Four samplings were carried out during the dry and rainy seasons in 2014, in two biotopes (plankton and aquatic macrophytes) to assess the composition and species richness of testate amoebae community in a coastal stream in the state of Rio de Janeiro, Brazil. Results showed great representation of Difflugiidae, Centropyxidae, Lesquereusiidae and Arcellidae families. Higher richness was observed in the plankton samples and higher densities of testate amoebae were reported among the aquatic vegetation during the dry season. Current investigation is a pioneer study conducted in the Ubatiba stream. Further researches on these protists, especially in Rio de Janeiro, should be undertaken.

Occurrence of Arcellidae (Amorphea, Arcellinida) in a coastal stream in the State of Rio de Janeiro

“…Water level is solely regulated by, and fluctuates according to, rainfall and run-off with abundant summer rain, enhancing water fluctuations (November to January) (Mazzoni & Lobón-Cervià, 2000). Riparian vegetation is altered in some parts of the stream, but remnants of Atlantic Forest are still present on the tops of surrounding hills (Miranda & Mazzoni, 2015) (Figure 1).…”

“…These protists inhabit different biotopes such as riparian vegetation, periphyton, sediment and plankton in continental waters (Alves, Velho, Costa, & Lansac-Tôha, 2012;Miranda & Mazzoni, 2015). Most studies on testate amoebae focuses on lentic systems (standing water or little movement environments) (Fulone, Vieira, Velho, & Lima, 2008;Tôha et al, 2014).…”

“…Some authors such as Crispim and Watanabe (2000) and Wetzel (2001) suggest that the advective or continuous turbulence downstream of an aquatic ecosystem, considered as the primary factor, negatively affects the development of these groups in this type of environment (Neves, Serafim-Júnior, Ghidini, & Brito, 2007). Considering lotic environments, particularly low order, such as streams, few studies include these organisms, although they are frequent and sometimes dominant in these environments (Fulone, Lima, Alves, Velho, & Lansac-Tôha, 2005;Fulone et al, 2008;Miranda & Mazzoni, 2015).…”

“…Arcellidae is one of the most common testate amoebae families in neotropical aquatic ecosystems, ubiquitous in many types of environments across the world (Vucetich, 1978;Miranda & Mazzoni, 2015;Silva, Rangel, Lansac-Tôha, Schwind, & Joko, 2016). Species of this family build their shells with endogenous material and present discoid or hemispherical shape and centered pseudostoma (Souza, 2008).…”

“…Thus, given the importance of testate amoebae in continental aquatic environments and the scarcity of research related to these protists in low order lotic environments, especially in the State of Rio de Janeiro (Miranda & Mazzoni, 2015), the present study aimed to describe and illustrate the testate amoebae taxa of Arcellidae from a coastal stream. In addition, we aim to contribute to the knowledge about the occurrence and geographic distribution of these organisms in this State and in the Southeast region of Brazil.…”