Diet composition of abundant fish species in the shallow waters of the Todos os Santos Bay, Bahia, Brazil

Rafael Lima Oliveira,Alexandre Clistenes De Alcântara Santos,Leonardo Evangelista Moraes

doi:10.4025/actascibiolsci.v43i1.52230

Abstract

Coastal habitats have great ecological importance with estuarine environments providing feeding sites for many fish species, especially during juvenile life stages. This study investigates the diet composition and trophic guild organization of the common and abundant ichthyofauna in shallow areas of the Todos os Santos Bay (TSB), Bahia, Brazil, and their relationships with environmental parameters. Six fish sampling campaigns were carried out in the shallow zones (infralittoral) of the Paraguaçu River estuary which encompasses the inner and outer (marine exposure) reaches of the TSB. The stomach contents of 1231 individuals belonging to common and abundant species were examined. A total of 32 food items were identified and fish were into four trophic guilds: detritivores, zoobenthivores I, zoobenthivores II, and zooplanktivores. The relationship between the guilds and environmental parameters showed that zoobenthivores II and zooplanktivores guilds had a positive relationship with salinity and pH, explaining 86% of data variability, though only the salinity variable was significant. This study provides basic information about the diet composition of common and abundant species in the TSB and their organization into trophic guilds. In addition, demonstrates that shallow waters fish across all guilds have broadly similar diets, comprising food items that are usually associated with bottom waters.

Highlights

Studies on food ecology provide valuable insights into the complex interactions between species and their environment (Berg, 1979; Ferry & Cailliet, 1996; Brodeur, Smith, Mcbride, Heintz, & Farley, 2017)
The study was conducted in the Todos os Santos Bay (TSB), located at 12°50’05” S, 38°46’20” W (Figure 1)
Most fish species found in estuarine environments have morphological and physiological adaptations that allow them to feed on the estuarine floor, indicating that substrate plays an important role in the functioning of trophic webs (Day, Yanz-Aranciba, Kemp, & Crump, 2012)

Summary

Introduction

Studies on food ecology provide valuable insights into the complex interactions between species and their environment (Berg, 1979; Ferry & Cailliet, 1996; Brodeur, Smith, Mcbride, Heintz, & Farley, 2017). Evaluating the diet and dietary aspects of species is still a primary concern in general and applied ecology (Albouy et al, 2011). These studies provide basic information on ecological aspects and the life history of many species, as well as the role of species in the trophic structure and organization of aquatic ecosystems (Brown, Bizarro, Cailliet, & Ebert, 2011; Braga, Bornatowski, & Vitule, 2012). Coastal habitats are of great ecological importance Within these regions, the estuarine environments stand out for their use as feeding sites by many fish species, especially during juvenile life stages. Considered to be one of the most productive aquatic ecosystems, the availability of food resources in estuarine areas can be a key factor in limiting the growth and survival of juveniles (Blaber, 2000; Martinho, Cabral, Azeiteiro, & Pardal, 2012; Potter, Tweedley, Elliott, & Whitfield, 2013)

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Discussion

Conclusion