Cladocera (Crustacea, Branchiopoda) of a temporary shallow pond in the Caatinga of Pernambuco, Brazil

Abstract

-The aim of this study was to describe the composition and structure of cladocerans of littoral areas with and without macrophytes from a temporary shallow pond in the Caatinga of Pernambuco state (Brazil). Samples were taken between June 2011 and August 2012. The sampling of cladocerans and environmental variables was performed at four fixed points, using a plankton net (45 μm) and a multiparameter probe. Twenty-two cladoceran species were recorded, with two new occurrences for Pernambuco state: Chydorus cf. brevilabris and Macrothrix superaculeata. The species richness of non-planktonic cladocerans (16) was higher than that of planktonic ones (4). The mean density was 186.7 ± 273.6 ind. L -1 . Macrothrix elegans, Diaphanosoma spinulosum and Ephemeroporus hybridus were the most abundant. The fluctuation index of the main species showed greater instability during the driest months or greater rainfall, a pattern not observed for the environmental data. However, the pond did not show limnological and cladoceran structure differences between the dry and rainy seasons and between the areas with and without macrophytes. With the exception of temperature and rainfall, the structure and richness of cladocerans was not related to the fluctuation of the other variables. Warmer months had higher densities and richness of cladocerans. On the other hand, months of greatest rainfall had lower richness, especially for the Chydoridae family. Although this Caatinga pond is maintained exclusively by rainwater, the richness of cladocerans is high when compared to other tropical and subtropical ecosystems. These results suggest that rainfall and temperature exert greater control on the dynamics of cladocerans in the Caatinga's temporary shallow ponds, and demonstrate the importance of these ecosystems to biodiversity in the semiarid region.

INFLUÊNCIA DOS PARÂMETROS ABIÓTICOS NA ABUNDÂNCIA DE Biomphalaria straminea (BASOMMATOPHORA: PLANORBIDAE) EM UMA LAGOA TEMPORÁRIA NO SEMIÁRIDO DE PERNAMBUCO, BRASIL

“…Possui uma área de 887,24 ha e está localizado na unidade de paisagem depressão sertaneja, uma paisagem típica do semiárido nordestino, com relevo predominantemente suave e ondulado, baixa pluviosidade e vegetação predominante de Caatinga (Sá et al 2003). De acordo com Diniz et al (2013), o PEMP possui duas lagoas e um riacho temporários, além de possuir uma rica diversidade de fauna e flora.…”

“…A região semiárida brasileira caracteriza-se pela irregularidade hídrica e formação de lagoas temporárias, ecossistemas de grande importância já que consistem em ambientes naturais com acúmulo de água durante o período de chuvas (Simões et al 2008). As lagoas podem secar na estação seca ou em períodos prolongados de estiagem, embora muitas vezes, mesmo no período chuvoso, as chuvas não sejam capazes de manter os ecossistemas lênticos inundados durante um longo tempo (Diniz et al 2013).…”

Water quality and plankton biota of Osinmo reservoir, Osun State, south-west Nigeria

“…The non-availability of cladocerans during the late rainy season may be due to the impact of rain on their proliferation (Venkataraman 2000). Diniz et al (2013) also observed lower richness of cladocerans in months of heavy rainfall. Low pH level as a result of influx of water due to heavy rain during the period might have also led to non-availability of Charophyta during this period.…”

Can nearby eutrophic reservoirs sustain a differentiated biodiversity of planktonic microcrustaceans in a tropical semiarid basin?

“…However, about twice the number of cladocerans (22) can be found in a single temporarily shallow pond of the Caatinga in Pernambuco (near the studied reservoirs), which presents an extensive bank of aquatic macrophytes (Diniz et al 2013). The studied environments did not present aquatic macrophytes throughout every reservoir.…”

“…Among them, 120 species occur in Brazilian waters (Elmoor-Loureiro 2000), of which 55 were catalogued for Pernambuco State, a Central State in Northeastern Brazil (Soares and Elmoor-Loureiro 2011, Diniz et al 2013, Sousa et al 2015a. Among the freshwater copepods, more than 2000 species have been described all around the world.…”