Feeding ecology of Rivulus luelingi (Aplocheiloidei: Rivulidae) in a Coastal Atlantic Rainforest stream, southern Brazil

Abstract

Feeding habits of the killifish Rivulus luelingi collected in a black water stream of the Coastal Atlantic Rainforest in southern Brazil were investigated. Eight samplings were made between April 2003 and January 2004. The diet, assessed through a similarity matrix with the estimated contribution values of food items, included microcrustaceans, aquatic immature insects (larvae and pupae), aquatic adult insects, terrestrial insects, insect fragments, spiders, and plant fragments. Differences in the diet according to temporal variations (months) were registered, but changes related with size classes evaluated and high/low precipitation period were not observed. The species presented an insectivorous feeding habit, and its diet in the studied stream was composed of autochthonous (mainly aquatic immature insects) and allochthonous (mainly insect fragments) material.Neste estudo foram investigados os hábitos alimentares do peixe anual Rivulus luelingi em um riacho de água escura da Floresta Atlântica Costeira do Sul do Brasil. Oito amostragens foram realizadas entre abril de 2003 e janeiro de 2004. A dieta, avaliada através de uma matriz de similaridade com os valores de contribuição estimados para os itens alimentares, inclui microcrustáceos, insetos imaturos aquáticos, insetos aquáticos e terrestres, fragmentos de insetos, aranhas e fragmentos de plantas. Diferenças relacionadas ao período amostral (meses) foram registradas, mas mudanças na dieta em função das classes de tamanho avaliadas e o período de alta/baixa precipitação não foram observadas. A espécie apresentou hábito alimentar insetívoro, e sua dieta no riacho estudado foi composta por itens autóctones (principalmente insetos imaturos aquáticos) e alóctones (principalmente fragmentos de insetos).

Trophic ecology of Hemigrammus marginatus Ellis, 1911 (Characiformes, Characidae) in a conserved tropical stream

“…Young individuals of the first standard length class consumed a large amount of zooplankton. The ontogenetic variations in freshwater fish diet have been commonly reported in the literature (Hahn et al, 2000;Lima-Junior and Goitein, 2003;Cassemiro et al 2008;Mazzoni and Costa, 2007;Agostinho et al, 2009;Suiberto et al, 2009;Abilhoa et al, 2010;Lima and Behr, 2010;Mazzoni et al, 2010;Bonato and Fialho, 2014). The ontogenetic variations found in the H. marginatus diet in the Beija-Flor stream are determined by the size of the fish, prey and ease of predation of available food resources, as the fish become adults, predation by the zooplankton item undergoes a significant decrease.…”

“…The high consumption of terrestrial insects of the order Hymenoptera in the Beija-Flor stream may be associated with the conservation of the riparian vegetation in its surroundings. Thus, the relative importance of allochthonous or autochthonous food in stream fish communities depends on the specific environmental conditions of each region studied, such as the presence of riparian vegetation in the basin, transparency and water current, among others (Esteves and Aranha, 1999;Luz-Agostinho et al, 2006;Abilhoa et al, 2010).…”

“…Food resources originating from riparian vegetation play a major role in the fish diet, mainly in the wet season (Lowe-McConnell, 1987;Abilhoa et al, 2008Abilhoa et al, , 2010. Another important factor is the presence of macrophytes because they provide habitats that can influence the composition of the associated fauna and the interspecific relationships of the species in aquatic ecosystems (Thomas et al, 2010).…”

Trophic strategy of Atlantirivulus riograndensis (Cyprinodontiformes: Rivulidae), a non-annual rivulid threatened by extinction, in a perennial environment, Brazil)

“…Autochthonous items were crucial in the diet of three other species of Atlantirivulus: A. haraldsiolii which is considered omnivorous (Abilhoa et al, 2010b), A. santensis consuming immature aquatic insects (Contente & Stefanoni, 2010), and A. luelingi which consumed 66% of food items of autochthonous origin and of these, Chironomidae larvae corresponded to the principal item (Abilhoa et al, 2010a).…”

“…The feeding pattern found for rivulids consists of consumption of autochthonous items, with ingestion of non-aquatic prey in certain cases (Laufer et al, 2009;Abilhoa et al, 2010aAbilhoa et al, , 2010b. For the genus Atlantirivulus in perennial coastal streams in the Mata Atlântica biome of southern Brazil, there are records of insectivorous or omnivorous dietary habits (Abilhoa et al, 2010a(Abilhoa et al, , 2010b. The wide availability of food resources follows seasonal and/or spatial trends (Lowe-McConnell, 1999;Abelha et al, 2001).…”