Benthic macroinvertebrates of a tropical lake: Lake Caçó, MA, Brazil

Abstract

Benthic communities are highly relevant in the study of aquatic ecosystems, both for their role in the functioning of the ecosystem and also as markers or indicators of paleo-conditions. Their distribution, as in other communities, is conditioned by abiotic and biotic factors and to their interactions, which determine the structure of the community that is established. The aim of this study was to determine the taxonomic composition, abundance and spatial distribution of the benthic community, by collecting at 20 sampling sites in Caçó Lake (State of Maranhão, Brazil). Seasonal variation in these community parameters was analysed and related to the seasonal displacement of the Intertropical Convergence Zone. The results indicated that changes occur in the taxa richness, diversity and density of the benthic species of this lake that are mainly related to seasonality. All those parameters were higher in the dry than in the rainy period. The family Chironomidae (Diptera, Insecta) was the most important component of the community, representing approximately 50% of the total benthic fauna of the lake. The identification of the Chironomidae currently occurring in Lake Caçó is relevant, even at the genus level, considering the fact that this group produces fossilizing remains and could perhaps be good paleolimnological and paleoclimatic tracers that could be used to make inferences on past lake and climate conditions. Keywords: benthic community, Chironomidae, Lake Caçó, tropical Limnology, macroinvertebrates. Macroinvertebrados bentônicos de um lago tropical: lago Caço, MA, Brasil ResumoAs comunidades bentônicas são relevantes nos ecossistemas aquáticos devido ao seu papel no seu funcionamento e também como marcadores ou indicadores de paleocondições. Sua distribuição, similarmente à de outras comunidades, é condicionada por fatores abióticos e bióticos e pela interação entre eles, determinando a estrutura da comunidade que se estabelecerá. O objetivo do presente trabalho foi determinar a composição taxonômica, a abundância e a distribuição espacial da comunidade bentônica, amostrando-se em 20 pontos na lagoa do Caçó (Estado do Maranhão, Brasil). As variações sazonais nas características desta comunidade foram analisadas e relacionadas ao deslocamento sazonal da Zona de Convergência Intertropical. Os resultados indicaram que ocorrem mudanças na riqueza de taxons, diversidade e densidade da comunidade bentônica deste lago que são principalmente relacionadas à sazonalidade. Todas as variáveis analisadas foram maiores no período seco do que no chuvoso. Os organismos pertencentes à família Chironomidae (Diptera, Insecta) foram os mais importantes componentes da comunidade, representando aproximadamente 50% do total da fauna. A identificação dos Chironomidae atualmente presentes no Lago Caçó, mesmo em nível de gênero, é relevante, considerando-se o fato de que as larvas deste grupo produzem remanescentes fósseis que podem ser bons traçadores paleolimnológicos e paleoclimáticos, podendo ser utilizados para fazer inf...

Relationship between space distribution of the benthic macroinvertebrates community and trophic state in a Neotropical reservoir (Itupararanga, Brazil)

“…Branchiura sowerbyi = Bra; Chironomus spp -Chi; Limnodrilus hoffmeisteri = Lim; Saetheria sp = SAE; Pelomus sp = Pel; spp = Tant; Fissimentum sp = Fis; Goeldichironomus sp = Goe; Chaoborus sp = Cha; Procladius sp = Pro. (Callisto et al 2005, Pamplin et al 2006, Lucca et al 2010). The richness observed in Itupararanga Reservoir, which has eutrophic and mesotrophic conditions, suffering human impacts especially in the headwater, can be considered intermediate when compared with that described to other lentic environments in Neotropical Regions.…”

“…The richness observed in Itupararanga Reservoir, which has eutrophic and mesotrophic conditions, suffering human impacts especially in the headwater, can be considered intermediate when compared with that described to other lentic environments in Neotropical Regions. Lucca et al (2010) analyzed the benthic macroinvertebrates communities in an oligotrophic lake and recorded 23 taxa. Fusari & Fonseca-Gessner (2006) reported 20 and 34 taxa in an eutrophic and an oligotrophic reservoir, respectively.…”

The rainy season increases the abundance and richness of the aquatic insect community in a Neotropical reservoir

“…The reason for this fluctuation is that the environments are more stable in the dry season, allowing species colonization and establishment; in the rainy season, however, only species with morphological adaptations that allow them to resist the force of the water and the constant disturbances caused by rain can survive (Bispo and Oliveira, 1998;Bispo et al, 2001). This pattern was observed in a tropical lake (Lucca et al, 2010) dominated by Chironomidae and Oligochaeta in both seasons but with a higher density in the dry season. Although it is known that the damming of a river can strongly alter the structure of the zoobenthic community (Jorcin and Nogueira, 2008), the temporal pattern of this particular community is still not well understood.…”

Assessment of benthic macroinvertebrates at Nile tilapia production using artificial substrate samplers

“…Other studies have reported the prevalence of the Chironomidae group in different types of environments, as reported by Lucca et al (2010) in a tropical lake (Northeast region, Brazil), and Reis et al (2012), who evaluated 45 lotic sites in the Peixe Angical reservoir (North region, Brazil) and observed a greater number of genera in the subfamily Chironominae, although the subfamily Orthocladiinae (considered less tolerant to organic pollution) had been prevalent (genus Cricotopus was the most abundant one).…”