Estrutura da assembleia ictioplanctônica em dois estuários tropicais de Pernambuco (Brasil), sujeitos a diferentes condições hidrológicas

Abstract

RESUMOEste trabalho objetivou comparar a estrutura da assembleia ictioplanctônica em dois complexos estuarinos de Pernambuco (Rio Formoso e Suape), e relacioná-la com a variação de fatores hidrológicos. Foram feitas coletas bimestrais (abril/2012 a fevereiro/2013) com rede de plâncton (abertura de malha de 500 µm). Foi registrado um total de 2383 larvas de peixes para os dois estuários. As larvas identificadas pertencem a 34 famílias, 30 gêneros e 13 espécies. As famílias com maior abundância relativa nos dois estuários foram: Engraulidae (27%), Clupeidae (23%), Gobiidae (20%) e Sciaenidae (7%), além de Belonidae, Pomacentridae, Carangidae (3% cada) e Achiridae (2%), tendo os demais táxons juntos representado 12%. A elevada densidade larval de Clupeidae e Engraulidae sugere que há uma intensa atividade reprodutiva desses peixes em Rio Formoso e Suape, sendo Clupeiformes o grupo mais abundante em ambos. Os dois complexos estuarinos apresentaram assembleias larvais de peixes semelhantes, com maior contribuição de famílias marinhas em Suape, que apresentou salinidade mais elevada. O estuário de Rio Formoso apresentou maior riqueza, diversidade e equitabilidade, indicando maior estabilidade ecológica que o estuário de Suape.Palavras-chave: Clupeiformes, estrutura de comunidade, larvas de peixes Structure of the ichthyoplanktonic assemblage in two tropical estuaries of Pernambuco (Brazil), subject to different hydrological conditions ABSTRACTThis study aimed to compare the structure of the ichthyoplanktonic assemblage in two estuarine complexes of Pernambuco (Rio Formoso and Suape), and relate it to the variation of hydrological factors. Samples were taken bimonthly (April 2012 to February 2013) with a plankton net (500 µm mesh size). A total of 2,383 fish larvae was recorded for the two estuaries. The identified larvae belong to 34 families, 30 genera and 13 species. Families with higher participation in both estuaries were Engraulidae (27%), Clupeidae (23%), Gobiidae (20%) and Sciaenidae (7%), followed by Belonidae, Pomacentridae, Carangidae (3% each) and Achiridae (2%), while the remaining taxa represented 12%. The high larval density of Clupeidae and Engraulidae suggests that there is an intense reproductive activity of these fishes in Rio Formoso and Suape, Clupeiformes being the most abundant group in both estuaries. The two estuarine complexes have similar larval fish assemblages with higher contribution of marine families in Suape, where the highest salinity was recorded. The estuary of Rio Formoso showed greater richness, diversity and equitability, thus indicating it has a greater ecological stability than Suape.

Diversity of settlement‐stage reef fishes captured by light‐trap in a tropical south‐west Atlantic Ocean coastal reef system

“…Surveys using light traps have already been performed in various types of habitats and regions of the world, such as the Great Barrier Reef, Australia (Doherty, 1987;Fisher & Bellwood, 2002;Milicich & Doherty, 1994), Caribbean Sea (Wilson, 2001), New Zealand (Hickford & Schiel, 1999), coast of California, USA (Steele et al, 2002), Mediterranean Sea (Felix-Hackradt et al, 2013) and Africa (Valles et al, 2001). However, in Brazil, most studies of marine fish larvae have used plankton nets and have focused on estuarine habitats (Dantas et al, 2013;Ekau et al, 1999;Marcolin et al, 2010;Marques et al, 2015;Severi et al, 2008;Souza et al, 2010). Thus, the composition of settlement-stage larval reef-fish assemblages remains poorly known.…”