The seasonal diet of Aequidens tetramerus (Cichlidae) in a small forest stream in the Machado River basin, Rondônia, Brazil

Abstract

Trophic relationships in fish communities are affected by the availability of resources, which in turn is affected by spatial and temporal variations throughout the year. The aims of this study were to characterize the diet of A. tetramerus in a streamlet in the north of Brazil and compare its composition in different hydrological seasons (wet and dry seasons). Collections were performed every two months from October 2011 to September 2012 with the aid of seine nets, hand net and fishing traps in the streamlet located in the Machado River drainage basin in the Rondônia state. Most of the specimens collected were quite small (< 40 mm) and had empty stomachs. Our results showed that A. tetramerus feeds on a wide variety of items of plant origin, such as algae, seeds and leaves, as well as items of animal origin, including bryozoans, crustaceans, fish scales, terrestrial insects and detritus. The data also indicated higher consumption of aquatic insects than other food items, suggesting a primarily insect-based diet. Items of plant and allochthonous origin were consumed more in the wet season than in the dry season, but there were no seasonal differences in the consumption of animal and autochthonous items. KEYWORDS: Fish, Perciformes, Amazon, feeding habits, ornamental fish. Dieta sazonal de Aequidens tetramerus (Cichlidae) em um igarapé da bacia do rio Machado, Rondônia, Brasil RESUMORelações tróficas das comunidades de peixes são afetadas por variações espaciais e temporais, que alteraram a disponibilidade de recursos ao longo do ano. Os objetivos deste estudo foram caracterizar a dieta de A. tetramerus no igarapé estudado, bem como comparar se a composição dos itens da dieta desta espécie dependem da estação hidrológica (período chuvoso e seco). As coletas foram realizadas bimestralmente, de Outubro de 2011 a Setembro de 2012, com auxílio de picaré, puçá e covos em um igarapé localizado na bacia do rio Machado no estado de Rondônia. A maioria dos espécimes eram pequenos (< 40 mm) e tinham estômago vazio. Observou-se que A. tetramerus se alimenta de uma grande variedade de itens de origem vegetal, como algas, sementes e folhas; e de itens de origem animal como: briozoários, crustáceos, escamas, insetos terrestres e detritos. Constatou-se que há maior consumo de insetos aquáticos, o que sugere uma dieta insetívora. Itens de origem vegetal e alóctones foram mais consumidos na estação chuvosa do que na estação seca. Não houve diferença na composição da dieta dos peixes entre as estações de seca e chuva.

Feeding ecology of Serrapinnus notomelas (Characiformes: Cheirodontinae) in small forest streams in the Machado River basin, Rondônia, Brazil

“…The importance of allochthonous Feeding ecology of Serrapinnus notomelas (Characiformes: Cheirodontinae) in small forest streams in the Machado River basin, Rondônia, Brazil ACTA AMAZONICA material for the feeding of stream fishes is relevant (Nogueira and Costa 2014;Kemenes and Forsberg 2014;Costa and Soares 2015). This shows that S. notomelas depends almost exclusively on resources provided by the terrestrial environment.…”

Insect meals in fish nutrition

“…) and include aquatic insects in the adult and/or larval stages in the orders Diptera, Trichoptera, Odonata, Hemiptera, Coleoptera and Ephemeroptera (Ribeiro et al . ; Costa & Soares ; Pereira Neves et al . ; Severo‐Neto et al .…”

Forest fragmentation influences the diet of cichlids Apistogramma agassizii (Steindachner, 1875) and Aequidens tetramerus (Heckel, 1840) (Actinopterygii: Cichliformes) in streams of the Western Amazon

“…They belong to the order Cichliformes, being the third most diversified family of neotropical freshwater fish (Reis et al, 2003). South American cichlids, especially small ones, have a wide variety of reproductive and food adaptive strategies (Sampaio & Goulart, 2011) and, therefore, can respond to changes in the environment (Costa & Soares, 2015).…”

“…The cichlid species Apistogramma agassizii (Steindachner, 1875) and Aequidens tetramerus (Heckel, 1840) can be found foraging in the same microhabitat (Costa & Soares, 2015). They are widely distributed in a variety of habitats, such as lowland lakes, aquatic vegetation, and small streams, where aquatic insects are the dietary basis of these two species (Cardoso & Couceiro, 2017).…”