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Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences
RESEARCH ARTICLE

What happens in the darkness? Seasonal variations in tropical benthic fish assemblages

C. Duarte https://orcid.org/0000-0002-1036-5850 A , H. M. V. Espírito-Santo B C , J. Zuanon D , L. H. Rapp Py-Daniel D E and C. P. Deus D
+ Author Affiliations
- Author Affiliations

A Programa de Pós-Graduação em Biologia de Água Doce e Pesca Interior, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, 69060-001 Manaus, AM, Brazil.

B Núcleo de Ecologia Aquática e Pesca da Amazônia, Universidade Federal do Pará, Avenida Augusto Corrêa, 01, 66070-375 Belém, PA, Brazil.

C Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, Rua das Biociências, 59078-970 Natal, RN, Brazil.

D Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, 2936, 69060-001 Manaus, AM, Brazil.

E Programa de Coleções, Coleção de Peixes, Campus II, Avenida André Araujo, 2936, 69060-001 Manaus, AM, Brazil.

F Corresponding author. Email: cleberduarte08@gmail.com

Marine and Freshwater Research 71(4) 419-431 https://doi.org/10.1071/MF19038
Submitted: 4 February 2019  Accepted: 7 May 2019   Published: 19 August 2019

Abstract

Studies of fish assemblages have demonstrated that the main channels of rivers contain ichthyofauna adapted to this environment. However, information regarding the effects of temporal and spatial variations on this ichthyofauna is scarce. Using data from benthic fish assemblages in a major tributary of the Amazon basin collected during two consecutive receding and two rising water seasons, we tested the hypothesis that there are marked variations in community composition between the receding and rising water seasons. An asymmetry in predictability was detected among samples from the receding and rising seasons. Predictability in terms of species composition was higher for receding than rising seasons. The continual disassembly and reassembly cycles (due to dispersal) of local communities across a spatially heterogeneous landscape could explain this difference. Depth and dissolved oxygen affected the distribution of some benthic fish species during the rising seasons. This study highlights the important contribution of marginal wetlands to the benthic ichthyofauna inhabiting the main channel of the Purus River, as well as other major Amazonian rivers.

Additional keywords: diversity, environmental variables, flood plain, Purus River, richness, seasonality.


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