Dieta de espécies de Anostomidae (Teleostei, Characiformes) na área de influência do reservatório de Manso, Mato Grosso, Brasil

Abstract

ABSTRACT. Diet of Anostomidae species (Teleostei, Characiformes) in the influence area of Manso Reservoir, Mato Grosso, Brazil. The diet of four species of Anostomidae (Leporinus friderici Bloch, 1794, L. striatus Kner, 1858, L. elongatus Valenciennes, 1849 and Leporinus sp.) were investigated in the Manso Reservoir, Mato Grosso State, Brazil. Fish were sampled in three sites: upriver, in the main body of the reservoir, and below the dam. Were analized 276 stomachs. The diet was evaluated using the frequency of ocorrence and volumetric methods. Leporinus friderici showed tendency to herbivory, mainly in the upriver site. In the reservoir and below the dam, it consumed large quantities of fish; Isoptera only in the reservoir. Leporinus striatus and L. elongatus have similar diets, consuming Chironomidae larvae (Diptera), whereas Leporinus sp. was more generalist, feeding similar proportions of vegetable, detritus and insect (Chironomidae and Ephemeroptera). INTRODUÇÃOA flexibilidade de hábito alimentar é uma característica adaptativa do comportamento animal, uma vez que ambientes naturais variam espacial e temporalmente, sendo que os peixes respondem à baixa disponibilidade alimentar alterando seu comportamento. Em reservatórios recém-formados, alterações no comportamento alimentar dos peixes são esperadas, principalmente em função da incorporação de material terrestre ao sistema aquático (AGOSTINHO et al., 1999) e do incremento da produção em todos os níveis tróficos (O'BRIEN, 1990), que pode alterar temporariamente a disponibilidade dos recursos alimentares. Espera-se que espécies estreitamente relacionadas apresentem, no mínimo, estratégias e táticas comportamentais diferenciadas que permitam a co-existência. Em relação à partilha de recursos alimentares, espécies de peixes congenéricas ou mesmo simpátricas têm mostrado, além de diferenças comportamentais (AGOSTINHO et al

Ecomorphological differences between Rhamdia (Bleeker, 1858) populations from the Iguaçu River basin

“…Casatti et al 2005, Balassa et al 2004, Santos et al 2011). Resource partitioning is considered the principal factor in structuring the aquatic communities (Ross 1986).…”

Endoparasite fauna of Brycon amazonicus and B. melanopterus(Characidae, Bryconinae) from Negro and Solimões rivers, Amazon, Brazil

“…Several studies have observed that the reproductive migration pattern of a host can be a determining factor in the composition and structure of parasite communities, as the short and long migrations performed by this species over its lifetime permit the fish to exploit diverse environments, increasing the possibility of infection/infestation by diverse species of parasites (Lizama et al 2006). Consequently, these divergent migratory characteristics may affect the endoparasite fauna, as related species usually exhibit divergent characteristics that make the coexistence possible (Dogiel 1961;Balassa et al 2004).…”

Feeding aspects of Leporinus amblyrhynchus (Characiformes: Anostomidae) in the first stages of formation of a Neotropical reservoir, Brazil

“…of the water), the filling phase of reservoirs has been marked by the ingestion of termites (Isoptera) that float on the water (Durães et al, 2001;Albrecht & Caramaschi, 2003a, b;Balassa et al, 2004). The differentiated morphology of the mouth seems to be a powerful mechanism that helps segregate species of Leporinus when several of them occur in the same environment, such as in the reservatório of Manso (Balassa et al, 2004).…”

“…The differentiated morphology of the mouth seems to be a powerful mechanism that helps segregate species of Leporinus when several of them occur in the same environment, such as in the reservatório of Manso (Balassa et al, 2004). The feeding activity of L. amblyrhynchus is considered discontinuous in view of the fluctuations verified in the capture of food during a daily cycle.…”