Trophic ecology of speckled peacock bass Cichla temensis Humboldt 1821 in the middle Negro River, Amazon, Brazil

Abstract

The aim of this study was to analyse the trophic ecology of speckled peacock bass Cichla temensis inhabiting two tributaries of the middle Negro River, the Aracá River and the Demeni River. Using an analysis of stomach contents and stable isotope composition (δ15N, δ13C) of scales, we describe the diet and evaluate the trophic position of subadult and adult individuals. We then test whether diet shifts and trophic positions occurred among successive size classes and among sample locations. The stomach content analysis confirmed the piscivorous feeding habit of the species and showed that the speckled peacock bass preyed on a variety species belonging to different trophic guilds. The length of the ingested prey increased with the size of the speckled peacock bass. Diet composition and trophic position were not different among size classes. δ13C values yielded significant shifts among the size classes: larger individuals displayed higher δ13C values than smaller individuals. Trophic position varied between locations, with lowest values observed in fish from the Aracá River. This study demonstrated that diet of C. temensis may vary according to the size of the fish, even at the subadult or adult stages, and according to the river/locality, even within a same basin. We then suggest that further studies take into account local availability of food resources to better explore C. temensis diet and tropic ecology.

Length‐weight relationship of 16 fish species from the Negro River basin (Amazonas state, Brazil)

“…The Aracá River is formed by black waters that have recent deposition of organic matter on the surface, followed by a sandy layer which has a low organic matter content (<0.03%; Oliveira et al., 2011). However, the Demeni River is limnologically distinct with white waters and a low sediment load (Aguiar‐Santos et al., 2018; Sioli, 1984).…”

‘Taking Fishers’ Knowledge to the Lab’: An Interdisciplinary Approach to Understand Fish Trophic Relationships in the Brazilian Amazon

“…In the Amazon region, studies applying stable isotopes analysis to analyze trophic relationships have been conducted mainly in white and black water rivers (Araujo- Lima et al, 1986;Oliveira et al, 2006;Mortillaro et al, 2015;Aguiar-Santos et al, 2018;Carvalho et al, 2018), whereas fewer studies have been conducted in clear water rivers (Zuluaga-Gómez et al, 2016;Andrade et al, 2019). Clear water basins covering 27.3% of the total area of the Amazon basin and are the most impacted basins of the Amazon (Goulding et al, 2003).…”

SPATIAL AND SEASONAL VARIATION OF PEACOCK BASS (<i>Cichla</i> spp.) FISHERY: AN ANALYSIS OF CATCHES LANDED IN MANAUS, AMAZONAS STATE, BRAZIL

“…In the receding water season, when the habitat of the flooded forest becomes smaller, the peacock bass moves toward open water where it is easier to catch. This synchronic movement of the peacock bass with the water level is also related to greater prey availability near the banks of the rivers and lakes during this season (Rabelo and Araújo-Lima, 2002;Aguiar-SANTOS et al, 2018). Other studies also indicated the variability of landings according to river regime (Isaac et al, 2015;Sousa et al 2017;Lopes and Freitas, 2018).…”