Trophic ecology of Hemigrammus marginatus Ellis, 1911 (Characiformes, Characidae) in a conserved tropical stream

Abstract

The trophic ecology of ichthyofauna in a stream can be related to the presence or absence of riparian and aquatic vegetation, and mainly resource availability. Therefore, the aim of this study was to analyse the seasonal and ontogenetic variations for the trophic ecology of Hemigrammus marginatus in the Beija-Flor stream located at the Jataí Ecological Station in the municipality of Luiz Antônio-SP, Brazil. In order to attain this objective, the data collections were carried out on a monthly basis from August, 2011 to July, 2012. Fish were collected using a trawl net and bait traps from three collection stations distributed along the Beija-Flor stream. The quality of the water was evaluated by the chemical variables: ammonia, nitrate, total nitrogen, total phosphorus, and physical temperature, dissolved oxygen, pH, turbidity and conductivity, obtained by using a Yellow Springs sonde. The collected specimens were fixed in 10% formalin in the field and were subjected to biometric measurements in the laboratory. The stomachs were weighed and transferred to 70% alcohol and the stomach contents were analysed using a stereomicroscope at the lowest possible taxonomic level. The species was considered insectivorous and the autochthonous food items were the most important during the dry season, mainly from the orders Ephemeroptera and Trichoptera, while allochthonous items from the order Hymenoptera were more important in the wet season. The young individuals' diet was based on the consumption of zooplankton, and insofar as the fish develops, there was a decrease in this item in the diet showing that the species has ontogenetic shifts in its diet. The conservation state of the Beija-Flor stream, as well as the flexibility of using food and food resources provided by aquatic macrophytes and riparian vegetation are key factors for the high abundance of the H. marginatus species.Keywords: stream fish, diet, ontogenetic variations, riparian vegetation, upper Paraná basin, seasonality. Ecologia trófica do Hemigrammus marginatus Ellis, 1911 (Characiformes, Characidae) em um riacho tropical conservado ResumoA ecologia trófica da ictiofauna em um riacho pode estar relacionada à presença ou ausência de mata ciliar e vegetação aquática, e principalmente pela disponibilidade de recursos no ambiente. Assim, o objetivo deste estudo foi analisar as variações sazonais e ontogenéticas na ecologia trófica de Hemigrammus marginatus no córrego Beija-Flor, localizado na Estação Ecológica de Jataí, localizada no município de Luiz Antônio-SP, Brasil. Para atender esse objetivo as coletas de dados foram realizadas mensalmente no período de agosto de 2011 a julho de 2012. Os peixes foram coletados utilizando rede de arrasto e armadilhas iscadas, em três estações de coleta distribuídas ao longo do córrego Beija-Flor. A qualidade da água foi avaliada pelas variáveis químicas amônia, nitrato, nitrogênio total, fósforo total, e físicas temperatura, oxigênio dissolvido, pH, turbidez e condutividade, obtidas com auxilio de uma sonda Yellow Sp...

Diet of Hemigrammus marginatus (Characiformes: Characidae) in the Upper Contas River, Diamantina Plateau (Bahia, Brazil)

“…In fact, environments with lentic characteristics, mainly in the marginal regions, favour the development of the zooplankton community (Esteves, 1988;Russo & Hahn, 2006). On the other hand, for the H. marginatus population from the Água Suja River, an environment with lotic characteristics, the category insects resulted in the greatest importance, a fact that was also observed in the Franco stream, Mato Grosso do Sul state (Brandão-Gonçalves et al, 2010), and in a preserved stream of the Atlantic Forest in São Paulo state (Fragoso-Moura et al, 2017). In the Água Suja River, the better conservation state of the marginal vegetation can be responsible for the considerable contribution of allochthonous material for the water body (Afonso et al, 2000).…”

Análise comparativa do antigo e o Novo Código Florestal: progresso ou retrocesso?

“…Logo, há estudos tanto nos biomas como Amazônia (ZELARAYÁN et al, 2015); Mata Atlântica (METZGER et al, 1997), Caatinga (VIEIRA et al 2017SCHLINDWEIN, 2009), e Cerrado (ZANZARINI; ROSELEN, 2009). Em relação aos grupos taxonômicos, há dados para árvores (METZGER et al, 1997), anfíbios (SABBAG; ZINA, 2011), peixes (FRAGOSO-MOURA et al, 2017), e abelhas (FARIA; SILVEIRA, 2011; MOURA; SCHLINDWEIN, 2009). Com isso, o conhecimento científico demonstra que a largura de APPs não são suficientes para manter a biodiversidade.…”

Grazing Unworried: Environmental Changes in a Dammed River Favor the Diet of the Invasive Metynnis Lippincottianus (Characiformes, Serrasalmidae)

“…The structure of food webs change in face of spatial and temporal variation (Woodward et al 2010, Fragoso-Moura et al 2016, Yu et al 2019. Rainfall seasonality is one of the primary factors structuring aquatic food webs and the diet of fishes in tropical freshwaters by changing the input of allochthonous resources to aquatic systems and habitat structure (Barbosa et al 2018, Pease et al 2020, Leal et al 2023.…”