Zooplankton community of Parnaíba River, Northeastern Brazil

Abstract

Aim:The objective of the present work is to present a list of species of zooplankton (Rotifera, Cladocera and Copepoda) from the Parnaíba River. Additionally, we provide comments on their distribution along the river, and between dry and wet seasons.MethodsZooplankton was collected with a plankton net (60 µm mesh) and concentrated into a volume of 80 mL for further analysis, during the dry (October 2010) and wet (April 2011) seasons. Sampling was restricted to the marginal areas at depths between 80 and 150 cm.ResultsA total of 132 species was recorded among the three zooplankton groups studied. During the dry season a total of 82 species was registered and 102 species was registered for the wet season. Rotifera contributed with 66.7% of the species, followed by Cladocera (26.5%) and Copepoda (6.8%).ConclusionsThe richness of species observed was high compared to other large rivers in Brazil. In the context of current policies for water management and river diversions in northeastern Brazil, the present study highlights the importance of this river system for biodiversity conservation.

Zooplankton community in the Upper Parnaíba River (Northeastern, Brazil)

“…The dominance of these two families is probably due to the great plasticity of the organisms of these families in relation to limnological conditions and food available. The species of these families are usually predominant in tropical rivers and lakes (e.g., Bonecker et al, 2009;Lansac-Tôha et al, 2009;Lucena et al, 2015). Among the cladocerans, the predominance of Chydoridae is common for river environments, although this type of environment is considered less favourable for the establishment of this group due to predation by fish and high water flow (Viroux, 2002), which suggests that life in lotic environments is related to some specialisation and adaptation to turbulence, which are not evident in cladocerans.…”

“…Ecological studies on the zooplanktonic fauna in the Parnaíba River channel are lacking. The few existing studies are mostly restricted to the fauna of rotifers and microcrustaceans (e.g., Medeiros et al, 2011;Lucena et al, 2015). Studies on testate protozoa are non-existent in the region, precluding comparisons.…”

“…The Brazilian semi-arid waterways are geomorphologically characterised as courses with no meanders and no floodplains, with floods restricted to the main river channel (Maltchik and Medeiros, 2006). On the other hand, during the floods, longitudinal connections between isolated water bodies seems to be an important factor in the spread and maintenance of biodiversity in these systems (Medeiros and Maltchik, 2001;Medeiros et al, 2011;Lucena et al, 2015).…”

“…In the northeastern Brazil, studies on the potamoplankton are scarce, highlighting recent work by Medeiros et al (2011) and Lucena et al (2015), although zooplankton studies in lentic environments are not uncommon to the region (e.g., Eskinazi-Sant'Anna et al, 2007;Almeida et al, 2009;Paranhos et al, 2013). The lack of extensive studies on the ecological processes of the Caatinga biome and its water courses, as well as the lack of knowledge about its biodiversity, has led to the incorrect perception that its aquatic biota is poor in species and endemism.…”

“…The most important issues in the conservation of the semi-arid rivers are the need for recognition of important areas to maintain biodiversity and that this biodiversity is closely associated with the natural patterns of flow and hydrological alterations (Maltchik and Medeiros, 2006). Without an understanding of how the extremes of flood and drought affect aquatic fauna, strategies for the conservation of rivers in the Brazilian semi-arid and their biota will not be effective (Maltchik and Medeiros, 2006;Lucena et al, 2015).…”