Feeding ecology of Serrasalmus gouldingi (Characiformes: Serrasalmidae) in the lower Anapu River region, Eastern Amazon, Brazil

Abstract

Studies on feeding ecology of fishes are important to understand the relationship between species and environmental seasonal variations. In tropical rivers, these relationships are mainly modeled by hydrological patterns. Thereby, this study aimed to assess the influence of fluviometric variation and life stage (juveniles and adults) in the feeding ecology of Serrasalmus gouldingi in the lower Anapu River region, located in Eastern Amazon, Pará, Brazil. Specimens were collected bimonthly, considering four different hydrological periods. We assessed the diet composition, feeding intensity and niche breadth of the species. Thirty-two dietary items were identified and grouped into ten categories. A total of 279 stomachs were analyzed, showing a predominance of fish fragments, followed by fruits and seeds. The diet composition of S. gouldingi differed only between drought and flood season, although it did not differ between juveniles and adults. An increase in feeding intensity was recorded during the rise in the water level, with a lower feeding intensity observed during transitional season. Serrasalmus gouldingi showed lower niche breadth during flood season, attributed to the high consumption of fruits and seeds, presenting an omnivorous diet with high tendency towards piscivory. Although less evident than in other Amazon watersheds, the flood pulse in the lower Anapu River region is an important factor influencing the feeding ecology of the species. KEYWORDS: Amazon basin, diet, flood pulse, niche breadth, repletion index.Ecologia alimentar de Serrasalmus gouldingi (Characiformes: Serrasalmidae) na região do baixo Rio Anapu, Amazônia Oriental, Brasil RESUMO Estudos sobre ecologia trófica dos peixes são importantes ferramentas para compreensão das relações entre as espécies e as variações sazonais no ambiente. Em rios tropicais essas relações são modeladas principalmente por variações hidrológicas. Sendo assim, o objetivo presente estudo é avaliar a influência variação fluviométrica e do estágio de vida (juvenis e adultos) na ecologia alimentar de Serrasalmus gouldingi na região do baixo Rio Anapu, Amazônia Oriental, Pará, Brasil. Os espécimes foram amostrados bimensalmente considerando quatro períodos hidrológicos distintos. Nós avaliamos a composição da dieta, intensidade alimentar e amplitude de nicho da espécie. Foram identificados trinta e dois itens alimentares agrupados em dez categorias. Um total de 279 estômagos foi analisado, registrando um predomínio no consumo de fragmento de peixes seguido por frutos e sementes. A composição na dieta de S. gouldingi diferiu apenas entre os períodos de seca e cheia, não diferindo entre juvenis e adultos. Uma maior intensidade alimentar foi observada durante o aumento do nível dos rios, com uma menor intensidade alimentar durante os períodos transicionais. Durante o período de cheia S. gouldingi também evidenciou uma menor amplitude de nicho, a qual foi atribuída ao elevado consumo de frutos e sementes. Sendo assim, a dieta de S. gouldingi foi classificada como...

Effect of flood pulses on the trophic ecology of four piscivorous fishes from the eastern Amazon

“…The feeding habits of Amazonian ichthyofauna are highly influenced by flood pulses (Correa & Winemiller, ; Goulding, ; Junk, ; Junk et al ., ). Seasonal variations in water levels enable the emergence of a wide variety of environments and change the availability of food resources for fishes (Barbosa et al ., ; Hahn & Fugi, ; Junk & Wantzen, ; Prudente et al ., ). Owing to the ephemeral nature of these environments, piscivorous fauna have several strategies to increase food capture and energy gain throughout the year.…”

Unexpected prey of juvenile spotted scat (Scatophagus argus) near a wharf: The prevalence of fouling organisms in stomach contents

“…They display various feeding patterns, such as planktonic and benthic (Gupta, ; Riemann et al., ), and can also adjust their feeding behaviors according to food availability in the natural environment (Prudente, Carneiro‐Marinho, Valente, & Montag, ). One such example is Serrasalmus gouldingi (Fink & Machado‐Allison 1992), which is the most abundant fish species in the Anapu River of the Amazon Basin (Prudente et al., ). The juveniles of this species have narrow food niches during droughts and early during periods when the water level rises, and at these times, they mainly consume other fish species.…”

“…levels. They display various feeding patterns, such as planktonic and benthic (Gupta, 2016;Riemann et al, 2010), and can also adjust their feeding behaviors according to food availability in the natural environment (Prudente, Carneiro-Marinho, Valente, & Montag, 2016).…”

“…One such example is Serrasalmus gouldingi (Fink & Machado-Allison 1992), which is the most abundant fish species in the Anapu River of the Amazon Basin (Prudente et al, 2016). The juveniles of this species have narrow food niches during droughts and early during periods when the water level rises, and at these times, they mainly consume other fish species.…”

BIOLOGIA DA ESPÉCIE Rhamdia quelen (QUOY E GAIMARD, 1824), (SILURIFORMES: PIMELODIDAE), NA MICROBACIA DO RIO QUEIMA-PÉ NO MUNICÍPIO DE TANGARÁ DA SERRA-MT, BRASIL

“…As análises do conteúdo estomacal em peixes é uma ferramenta muito utilizada e importante para compreender os padrões ecológicos nos ecossistemas, como a preferência alimentar no habitat que o peixe vive e as suas interações podendo ser correlacionadas com as variáveis ambientais e com a disponibilidade de recursos (PRUDENTE et al, 2016).…”