<b>Trophic structure of fish assemblages associated with macrophytes in lakes of an abandoned meander on the middle river Purus, brazilian Amazon

Abstract

The trophic structure of fish assemblages associated with banks of aquatic macrophytes in abandoned meander lakes on the river Purus is investigated. Comparisons between lakes and between different periods of the hydrological cycle are undertaken. Fish samples were collected in six lakes during the rainy (February), ebb (May) and dry (September) season in 2012. Fish stomach contents were analyzed by frequency of occurrence and volume methods, combined in the Feeding Index (IAi). Fish species were included in nine trophic categories, based on IAi rates. The richness and abundance of fish species, by trophic category, was influenced by temporal variations, with no significant spatial variation. Some species changed their diets and were included in different trophic categories according to the period and lake under analysis. Specialist species have also been identified, but failed to change their diets. Differences may be due to the characteristics of macrophytes banks and to the flooding regime which change the availability of food resources.

First study on communities of parasites in Triportheus rotundatus, a Characidae fish from the Amazon River system (Brazil)

“…The species of Triportheus inhabit most of the major river drainages of South America, and constitutes an important element in both commercial and subsistence fisheries in the Amazon basin (MALABARBA, 2004), its reproduction occurs during the rainy season in the Amazon River system (FROESE & PAULY, 2016). Triportheus rotundatus is a benthopelagic fish with an omnivorous diet, fed on fruits, seeds and insects that float on the water surface, besides microcrustaceans (PEREIRA et al, 2011;FROESE & PAULY, 2016;SUÇUARANA et al, 2016). However, studies on the biology of T. rotundatus are reduced, mostly those regarding its parasitic fauna.…”

Composition and diversity of phytophilous cladocerans of oxbow lakes of Southwest Amazonian, Acre state, Brazil

“…Aquatic plants confer important habitat heterogeneity in aquatic environments, and the unique spatial structure of plants is important for the growth and survival of the other aquatic organisms (Dibble & Thomaz 2006, Suçuarana et al 2016), such as phytophilous cladocerans.…”

Hábitos Alimentares Em Peixes De Água Doce: Uma Revisão Sobre Metodologias E Estudos Em Várzeas Brasileiras

“…É notável o maior número de estudos sobre a dinâmica populacional e estrutura ictiofaunística, quando comparado aos estudos do padrão de alimentação das espécies de peixes e metodologias para estudos da dieta em áreas de várzeas do Brasil. Apesar disso, podemos constatar significativo número de trabalhos tendo como enfoques principais a descrição dos hábitos, composição e a utilização de recursos alimentares (Bozza & Hahn, 2010, Isaac et al 2014, Tonella et al 2018, estrutura trófica (Suçuarana et al 2016, Dias et al 2017, amplitude e sobreposição de nicho (Novakowski et al 2008, Corrêa et al 2011, Dias et al 2017 e o efeito da sazonalidade sobre a dieta (Luz et al 2009, Röpke et al 2014, Cunha et al 2018.…”