FEEDING ECOLOGY OF <i>Cichlasoma amazonarum </i> (Teleostei, Cichlidae) IN THE CENTRAL AMAZON LAKES, BRAZIL.

Abstract

The diet of the cichlid Cichlasoma amazonarum was investigated through an analysis of 270 gastric contents obtained from monthly samples collected from five lakes located in the Central Brazilian Amazon, throughout the year of 2012. The composition of the diet was assessed using the methods of frequency of occurrence and relative dominance (frequency of biomass), which were combined in the Alimentary Importance Index (AIi) in accordance with the hydrological cycle's extreme periods of drought and high waters. The intestinal coefficient was investigated to demonstrate the feeding tendencies of the species. The breadth and diversity of the trophic niche were also compared for these periods. The intestinal coefficient for the species (0.95), combined with the results of the analysis of food content, showed a species that demonstrates carnivorous/insectivorous habits. During the high water season, the diet is composed of unidentified animal matter, unidentified larvae and insects; and in the drought season, plant matter, unidentified animal matter and insects. Although there was no significant difference in dietary diversity between seasonal extremes, the analysis of the breadth of the trophic niche characterises the species as feeding specialists.

Scale morphology is a promising, additional tool for exploring the taxonomy and ecology of freshwater fishes

“…The species list and the number of analysed scales per taxon are indicated in Table 1. To reveal the taxonomic position (order, family) and ecological characteristics (flow preference and preferred feeding habitat) of the investigated taxa, literature data (Abdurakhmanov, 1962; Cavalcante et al., 2014; Dadikyan, 1986; Derzhavin, 1937; Dresilign, 2003; Elanidze, 1983; Fricke et al., 2023; Levin et al., 2019, 2021; Nikolskiy, 1938; Reshetnikov, 2003; Sály & Erős, 2016; Turdakov, 1963) and online databases (Froese, 1990; URL1, n.d.; URL2, n.d.) were used (see Table 1 and Supplementary material).…”