Ecomorphology and diet reflect the spatial segregation between two Siluriformes species inhabiting a stream of the Bodoquena Plateau, in Central Brazil

Abstract

ABSTRACT. Pimelodella taenioptera Miranda Ribeiro, 1914 and Imparfinis schubarti (Gomes, 1956) are two of the most common fish species in Bodoquena Plateau streams, Paraguay basin. These species have benthic habits and subaquatical observations suggested that they present differentiation in their preference for mesohabitat types. Pimelodella taenioptera shows preference for slow waters, such as pools, while I. schubarti is associated to riffles. In this study we investigated if the known patterns of mesohabitat use of P. taenioptera and I. schubarti can be predict by their ecomorphological and trophic traits. We described the dietary habits and ecomorphological attributes of P. taenioptera and I. schubarti individuals, captured in the Parque Nacional da Serra da Bodoquena (PNSB), Mato Grosso do Sul state, central Brazil. Pimelodella taenioptera presented a more generalist diet, consuming a total of 23 different food items. Imparfinis schubarti have a diet based exclusively on aquatic insects. The ecomorphological analysis revealed that the species differed in relation to five morphological traits associated to habitat use (p <0.01). The results of this study reveal a clear functional dissimilarity between P. taenioptera and I. shubarti. The observed trophic and ecomorphological patterns are congruent with the known habitat use for these species and probably reflect the spatial and temporal variability on conditions and resources present in riffles and pools. Therefore, as expected, the morphological and feeding attributes represent predictive information related to mesohabitat use. KEYWORDS.Pimelodella, Imparfinis, ecomorphogical traits, mesohabitats, trophic ecology. RESUMO. Ecomorfologia e dieta refletem a segregação entre duas espécies de Siluriformes que habitam um córrego do Planalto daBodoquena, no Brasil Central. Pimelodella taenioptera Miranda Ribeiro, 1914 e Imparfinis schubarti (Gomes, 1956) estão entre as espécies de peixe mais comuns nos riachos do Planalto da Bodoquena, bacia do rio Paraguai. Estas espécies compartilham hábito bentônico, entretanto observações subaquáticas sugerem que estas espécies apresentam diferenças na preferência por tipos de mesohábitats. Pimelodella taenioptera apresenta preferência por habitats lênticos, tais como poços, enquanto I. schubarti é associado a corredeiras. Neste estudo, investigamos se os padrões conhecidos de uso de mesohábitats de P. taenioptera e I. schubarti predizem suas características ecomorfológicas e tróficas. Descrevemos os hábitos alimentares e os atributos ecomorfológicos de indivíduos de P. taenioptera e I. schubarti, capturados no Parque Nacional da Serra da Bodoquena (PNSB), Estado do Mato Grosso do Sul, Brasil Central. Pimelodella taenioptera apresentou dieta mais generalista, consumindo um total de 23 itens alimentares. Imparfinis schubarti apresentou dieta exclusivamente composta por insetos aquáticos. A dieta de P. taenioptera foi mais variável na estação chuvosa do que na estação seca (p=0,05) e foi significativamente mais variável do que a...

Insect meals in fish nutrition

“…; Severo‐Neto et al . ; Abilhoa et al . ) and terrestrial insects that primarily belong to the families Vespidae and Formicidae (Dyer et al .…”

Distribution, feeding and ecomorphology of four species of Auchenipteridae (Teleostei: Siluriformes) in Eastern Amazonia, Brazil

“…Understanding how ecomorphological traits showed by species in relation to environmental gradients is a basic premise for prediction of species distributions through a macroecology observation (Severo-Neto et al, 2015). In the present study, we described the distribution, diet and ecomorphology for four species from Auchenipteridae in the lower Anapú River (Eastern Amazonia).…”

“…Indirect methods, as ecomorphology, were also used for the description of the feeding and environmental tactics of the species (Winemiller, 1991;Severo-Neto et al, 2015).…”

Environmental assessment in tropical streams by using abundance-biomass curves and W index in fish assemblages

“…The explanation for this pattern is the ecological specificity (or specialization) of the species more correlated with PCoA1 and PCoA2 for both abundance and biomass data. The species more correlated with the urban (impacted) streams were those suited to live in siltation (a condition derived from low canopy cover and representative of low mesohabitat diversity), such as H. ancistroides (Casatti et al, 2005), I. schubarti (Severo-Neto et al, 2015), andH. strigaticeps (Jepep et al, 2007), with high feeding plasticity (impacted streams are frequently recorded as food resource restricted), like R. quelen (Gomiero et al, 2007), G. inaequilabiatus (Hahn et al, 2004), G. brasiliensis (Bastos et al, 2011), Bryconamericus iheringii (Oliveira & Bennemann, 2005;Oricolli & Bennemann, 2006), A. lacustris (Bennemann et al, 2005, under A. altiparanae), and O. paranensis (Abelha et al, 2012), adapted to feed on organic detritus (a typical food resource in impacted streams), as H. ancistroides and H. strigaticeps (Pagotto et al, 2011), and with high reproductive plasticity, as S. marmoratus (Favorito et al, 2005).…”