Environmental Biology of Fishes

, Volume 99, Issue 8, pp 647–658

Morphologic and trophic diversity of fish assemblages in rapids of the Xingu River, a major Amazon tributary and region of endemism

  • Mario Alejandro Zuluaga-Gómez
  • Daniel B. Fitzgerald
  • Tommaso Giarrizzo
  • Kirk O. Winemiller
Article

DOI: 10.1007/s10641-016-0506-9

Cite this article as:
Zuluaga-Gómez, M.A., Fitzgerald, D.B., Giarrizzo, T. et al. Environ Biol Fish (2016) 99: 647. doi:10.1007/s10641-016-0506-9

Abstract

Increasing hydropower expansion in hyper-diverse tropical river basins is currently threatening aquatic biodiversity on an unprecedented scale. Among the largest and most controversial of these projects is the Belo Monte Hydroelectric Complex being constructed on the Xingu River, a major Amazon tributary in Brazil. Despite the potentially large impacts, almost no baseline ecological data are available for the river’s diverse ichthyofauna. This study uses ecomorphology and stable isotope analysis to explore the functional and trophic relationships among four of the dominant families within the Xingu River rapids (Loricariidae, Cichlidae, Anostomidae, and Serrasalmidae). Morphological analysis revealed clear separation of these families based on functional traits associated with microhabitat use and foraging strategies, with the Loricariidae and Cichlidae displaying greatest functional diversity. The four families analyzed were not clearly differentiated in isotopic space defined by δ13C and δ15N values. Considerable overlap was observed among isotopic niches and all four families primarily assimilated material originating from phytomicrobenthos (assumed to be mainly benthic algae). Differences between morphological and trophic diversity within families provide insight into how this diverse assemblage may be partitioning niche space, which in turn has implications for population responses to hydrologic alteration.

Keywords

Rheophilic Neotropics Anostomidae Cichlidae Loricariidae Serrasalmidae Stable isotope Functional traits 

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  • Mario Alejandro Zuluaga-Gómez
    • 1
  • Daniel B. Fitzgerald
    • 2
  • Tommaso Giarrizzo
    • 1
  • Kirk O. Winemiller
    • 2
  1. 1.Laboratório de Biologia Pesqueria - Manejo dos Recursos AquáticosUniversidade Federal do ParaBelemBrazil
  2. 2.Program in Ecology and Evolutionary Biology and Department of Wildlife and Fisheries SciencesTexas A&M UniversityCollege StationUSA