Does the oscillation of the water volume of the reservoir influence in the same way in fish diet?

Abstract

Aim: To evaluate the fish feeding and to establish the preferential and secondary items of their diets, to determine the trophic guilds and the possible trophic structure variations in function of the water volume in Umari reservoir, Rio Grande do Norte, Brazilian semiarid. Methods: The fish were captured quarterly between February and November of 2013, with gill nets with different meshes, being the apparatuses exposed at 5:00 p.m., with removal at 5:00 a.m. The food items were identified using stereoscopic and optical microscopes and evaluated through the Feeding Index (IAi), being the results of this procedure used in food similarity analysis. The volume of the items was orderly in NMDS and the time differences were tested in PERMANOVA. Results: A total of 740 individuals belonging to 14 species were sampled, being analyzed a total of 258 stomachs and 8 intestines of 11 species. From the IAi values used in the trophic similarity analysis, the species were classified into five trophic guilds: detritivorous, insectivorous, malacophagous, carcinophagous and piscivorous. Conclusion: The oscillation in the water volume of the reservoir did not influence the diet of the guild detritivorous, which shows that the variations in the volume of water of the reservoir do not influence in the same way the diet of the local ichthyofauna.

Feeding patterns, trophic structure and damming rivers effect: studies applied in freshwater environments in the Brazilian semi-arid region

“…In this case, Astyanax bimaculatus was recorded in the Santa Cruz reservoir (Oliveira et al 2016b). However, recent study by Oliveira et al (2018) in the Umari reservoir, recorded A. bimaculatus as insectivorous. The species Leporinus taeniatus (Fowler, 1941), Leporinus elongatus (Valenciennes, 1850) in the Pau dos Ferros reservoir (Oliveira et al 2016a) and L. piau in the Santa Cruz reservoir (Oliveira et al 2016b) were also documented in the herbivorous guild and in the Pau dos Ferros reservoir (Oliveira et al 2016a).…”

“…Small-scale studies in reservoirs in the semi-arid region show that fishes present changes in dietary utilization and trophic structure due to changes in resources affected by drought and oscillations in the volume of water in the reservoirs (Oliveira et al 2016a;Oliveira et al 2016b;Oliveira et al 2018). In addition, the lack of rainfall in recent years has aggravated the water scarcity, causing an exacerbated decrease in the volume of water in the reservoirs, and a change in composition and fish abundance (Sousa 2015).…”

Feeding patterns, trophic structure and damming rivers effect: studies applied in freshwater environments in the Brazilian semi-arid region

“…Although reservoirs are common in the Brazilian semiarid region, few investigated about the impact of the flow fluctuation caused by dams. Small-scale studies in reservoirs in the semi-arid region show that fishes present changes in dietary utilization and trophic structure due to changes in resources affected by drought and oscillations in the volume of water in the reservoirs (Oliveira et al 2016a;Oliveira et al 2016b;Oliveira et al 2018). In addition, the lack of rainfall in recent years has aggravated the water scarcity, causing an exacerbated decrease in the volume of water in the reservoirs, and a change in composition and fish abundance (Sousa 2015).…”

RELAÇÃO DA INTEGRIDADE AMBIENTAL E A BIOLOGIA DE Serrapinnus notomelas (CHARACIDAE) EM CÓRREGOS URBANOS

“…Keywords: condition factor; diet; environmental pollution; gonadal development. estrutura trófica da comunidade aquática (Viana et al 2013), pois algumas espécies podem sofrer redução em suas populações, enquanto que outras, devido à plasticidade trófica, encontram condições favoráveis para alimentação, crescimento e reprodução, tornando-se mais abundantes (Silva 1993, Oliveira et al 2018.…”

“…Nesse contexto, o estudo da alimentação dos peixes é de extrema importância, tanto para aprofundar o conhecimento das características biológicas das espécies, mas também como um instrumento de compreensão das interações das diversas populações da ictiofauna e dos seus níveis tróficos na cadeia alimentar (Bennemann et al 2011, Viana & Vianna 2014, Viana et al 2017. Além disso, é por meio da alimentação que os indivíduos obtêm energia e, portanto, estudar a sua dieta auxilia na compreensão das atividades envolvidas no desenvolvimento, crescimento, reprodução e manutenção do organismo (Oliveira et al 2018). Dessa forma, investigações sobre a dieta dos peixes, através de estudos dos seus conteúdos estomacais, amparam a interpretação da dinâmica e ocupação de habitat por tais espécies (Brandão-Gonçalves et al 2009).…”