Trophic structure of the fish community throughout the reservoirs and tributaries of the Middle and Lower Tietê River (São Paulo, Brazil) (original) (raw)
Related papers
Brazilian Journal of Biology, 2004
With the purpose of determining the principal food resources responsible for maintaining the fishery yield in a section of the São Francisco River, 6 sampling of the fish fauna were made downstream from the Três Marias Dam, from September 1996 to July 1997. A total of 1,127 individuals of 35 species were captured, using gillnets with mesh sizes varying from 3 to 16 cm. The stomach contents of 33 species were examined in order to determine their diets. Five trophic guilds were established, in the following order of importance: ilyophagous, herbivorous, piscivorous, terrestrial invertebrates feeders, and aquatic invertebrates feeders. The resources sustaining the fish fauna were mainly of allochthonous origin. The ichthyonenosis appears to be mainly dependent on the detritus chain. The ciliary forest and seasonal flooding pulses are the main suppliers of food for the fish fauna.
Neotropical Ichthyology
This study was carried out in a section of the middle course of the Teles Pires River, a clear water river that drains ancient and highly eroded geological formations, and where five hydropower plants are planned or in construction. In this study we tested the hypothesis that local fish fauna is mainly sustained by autochthonous food resources, with modest changes in the trophic structure of fish assemblages along the hydrometric cycle. Sampling was performed every three months between July 2008 and May 2009 at seven sites distributed along a 50-km section of the river. Piscivores was the most representative group in terms of biomass, abundance and species richness, followed by herbivores, insectivores and omnivores. The trophic structure did not change significantly during the hydrometric cycle, only omnivores showed significant temporal variation in abundance. The main food resources consumed by the ichthyofauna were of autochthonous origin, mainly immature aquatic insects and fis...
Acta Scientiarum. Biological Sciences, 2016
We described the spatial distribution of fish trophic groups in the Água Boa Stream, MS, Brazil. Specimens were caught using electrofishing in the upper, intermediate and lower stretches of the stream, between March and November 2008. We analyzed 415 stomach contents of 24 species. Detritus/sediment and aquatic invertebrates were the main exploited resources. Ordination analysis categorized the species in six trophic groups. Aquatic invertivores showed the highest richness (10 species), followed by detritivores (08 species), omnivores (03 species), terrestrial invertivores (03 species), algivores (02 species) and herbivore (01 species). Three trophic groups occurred in the upper stretch, six in the intermediate and five in the lower. Detritivores, omnivores and algivores showed the highest density, while detritivores and aquatic invertivores presented the highest biomass. Autochthonous resources were particularly important to the studied fish fauna, especially aquatic invertebrates, so, conservation actions reducing the simplification of the habitat by silting and recovering the riparian forest are essential to maintain the ichthyofauna of the Água Boa Stream.
Feeding habits of fish from a stream in the savanna of Central Brazil, Araguaia Basin
Neotropical Ichthyology, 2004
The objective of the present study was to determine the composition of the diet of fish and its relation to the condition of canopy along a stream in the savanna of Central Brazil. Fish were collected monthly from April 1994 to March 1995. A total of 3872 individuals belonging to 82 species were captured and 1606 of them had their stomach content analysed. Allochthonous resources were widely used by fish. Although some fish groups do present generalist habits, most of the species can be included in well-defined trophic groups. Piscivores were abundant only during the flooding season when they occupied the stream looking for food and reproduction sites. Deforestation of the riparian forest has negative effects on the fish populations that depend on allochthonous resources. Lack of vegetation near the mouth of the river allows sand accumulation on the bottom of the stream and destruction of important microhabitats used as feeding and shelter, a fact that excluded some species from thi...
Environmental Biology of Fishes, 2004
We evaluated fish assemblage diet and trophic structure in five lakes (Patos, Zé do Paco, Fechada, Ressaco do Pau Véio and das Garças), connected or not with the river. Trophic structure analysis was based on the species whose number of sampled digestive tracts was greater or equal to 10 and ordinated according to a detrended correspondence analysis. We identified seven trophic guilds with the following representatives: (1) Detritivorous–ileophagous: Cyphocharax modestus, Prochilodus lineatus, Steindachnerina insculpta and Loricariichthys platymetopon; (2) Herbivorous: Schizodon borellii and Leporinus lacustris; (3) Benthophagous: Iheringichthys labrosus, Satanoperca pappaterra and Trachydoras paraguayensis; (4) Insectivorous: Astyanax altiparanae, Moenkhausia intermedia and Parauchenipterus galeatus; (5) Piscivorous: Hoplias cf. malabaricus and Serrasalmus marginatus; (6) Carnivorous–carcinophagous: Pimelodus maculatus and (7) Insectivorous–lepidophagous: Roeboides paranensis. The detritivorous–ileophagous guild was the predominant one in the five lakes.
Biodiversidade, 2014
The aim of this study was to evaluate the trophic ecology of the principal species of fish (Astyanax altiparanae, A. fasciatus, Bryconamericus stramineus, B. iheringii, Cheirodon stenodon, Characidium fasciatum, Geophagus brasiliensis, Hyphessobrycon anisitsi, Piabina argentea and Steindachnerina insculpta) captured in the littoral region of the Rio dos Veados (23º16'80''S/48º38'67''W), an affluent of the Rio Paranapanema, SP. The collections were conducted monthly with a seine-type trawling net with a 5.0mm mesh size, taking place between August, 1996 and December, 1997. This collection time was subdivided into the dry (April to September) and rainy (October to March) seasons. The food contents were analyzed by a volumetric method, and the food overlap determined by the Morisita-Horn index. The ten species of fish consumed different food resources, which varied in abundance (volume percentage): detritus/sediment (30.0%), aquatic insects (23.4%), microcrustaceans (17.6%), terrestrial insects (13.9%), higher plants (6.2%), algae (5.6%), fish (1.8%), and macroinvertebrates and microinvertebrates grouped together (1.5%). Patterns of similarity among the species were constructed utilizing Detrended Correspondence Analysis (DCA) with removal of the arch effect and tested by analysis of variance (unifactorial ANOVA), showing that there was no significant variation in the composition of food resources utilized by the species during the dry and rainy seasons. The main resources consumed by the ten species were classified into three trophic categories: omnivores, detritivores and insectivores. Interspecies food overlap revealed indices of 0.059 to 0.961, showing it to be independent of the period studied, since the resources utilized were similar, both in qualitative and quantitative terms. Intraspecies food overlap in the different periods was minimal for A. altiparanae (0.662) and maximal for S. insculpta (1.0). The species studied showed little variation in relative length of intestine, with the exception of S. insculpta which had an elevated intestinal index. The variations in food resources utilized between the periods were of little relevance, indicating that the temporal factor did not influence the resources utilized by the species studied. Of the ten species studied, nine could be viewed as generalists, considering the food resources utilized during the two periods, and only S. insculpta behaved as a specialist.
Brazilian Journal of Biology, 2008
The present study is inspired by the great wealth of species exhibited by the ichthiofauna. Not only concepts and techniques of ecology deserve attention, but also knowledge in other biological areas, such as zoology and anatomy, are necessary. The intention of the present work is to discover the morphology of fish through the study of the digestive tract morphology, associating it to diet data, in order to better understand the biology of four fish species of the upper Paraná River floodplain. The samples were collected quarterly in the year 2000 with gillnets of different meshes. The stomach content was analyzed under a stereoscopic microscope and the frequencies of occurrence (FO) and volumetric (FV) and the alimentary index (IAi) were calculated. Various morphologic characteristics were analyzed and schematized using a light chamber. The species were grouped into two trophic guilds - insectivores (Astyanax altiparanae and Parauchenipterus galeatus) and piscivores (Serrasalmus marginatus and Hoplias aff. malabaricus). The first two, although consumers of insects, preyed on different alimentary groups, notably Hymenoptera in the case of A. altiparanae and Coleoptera in the case of P. galeatus. Serrasalmus marginatus and H. aff. malabaricus consumed mainly fishes. However, only pieces of prey were usually found in the stomach content of the first species, whereas whole fishes were found in the stomach content of the second. Astyanax altiparanae exhibited characteristics that allowed it to obtain food in several compartments of the water column. Similarly P. galeatus consumed food resources that were available in all aquatic compartments, although the abilities to capture, to manipulate and to absorb food differed, as shown by the importance of teeth plates and pharyngeal teeth. Serrasalmus marginatus and H. aff. malabaricus, although resembling each other in many aspects of the digestive tract morphology, differed in the strategies used to capture prey. The analysis showed that, according to the main food item of the diet, the species were grouped into two trophic guilds. However, those within the same category used different feeding methods, and similarity in items consumed does not imply the same group of morphological characteristics.
Trophic guilds of fishes in sandbank habitats of a Neotropical river
Neotropical Ichthyology, 2007
The objective of this study was to characterize the trophic structure of the community of fishes exploiting riverine sandbank habitats. Collections were carried out during the period of October 1999 to December 2003, on six sand banks in the upper and middle portions of the Tocantins River drainage basin in central Brazil. The availability of food resources was evaluated based on the volume of the items present in the stomachs of all species. A total of 2,127 stomachs of fish belonging to 50 species were analyzed. Nine main trophic guilds grouped the local ichthyofauna according to diet. Aquatic-origin items were the preferred source for 55.5% of the groups analyzed, whereas terrestrial-origin items composed 44.4%. Items of undetermined origin (detritus and sediment), although present in 89% of the guilds, were the predominant food in only one trophic group. Terrestrial insects and fish were the food sources with the largest biomass available in the environment. Sandbank environments are homogeneous, with little shelter and food available; as a rule, the species that occupy these environments are generalists.
Neotropical Ichthyology, 2009
This study aimed to characterize the trophic structure of the fish assemblage in streams of the Serra Japi, an ecotonal area between the Atlantic Forest and inland forests of São Paulo State, Southeastern Brazil. Fish were collected with electrofishing equipment in 15 sites covering different regions, substrate types and riparian vegetation, distributed throughout the Caguaçú River, Caxambú, Piraí and Guapeva River micro-basins, during the rainy (January/February) and dry season (June) of 2007. The 589 specimens analyzed from 22 species, were assigned to different trophic groups, discriminated through a matrix of similarity, based on the food index (IAi). The results show the formation of seven groups with a predominance of insectivorous and omnivorous species, followed by detritivores, piscivores, omnivore-carnivores and herbivores, which consumed mostly items of autochthonous origin, where algae and young insects were dominant. Canonical correspondence analysis (CCA), correlating the biomass of trophic groups to environmental variables, showed that omnivores, insectivores and omnivore-carnivores displayed a wide distribution, while detritivores, herbivores and piscivores were restricted to specific locations, related to different physical and chemical variables as total nitrogen, conductivity and temperature. Despite the increase in total biomass at the most urbanized sites, the results indicate that the streams maintain a diverse community, suggesting that most of them are in preserved conditions.
Food resources used by three species of fish in the semi-arid region of Brazil
Temporary and semi-permanent aquatic habitats in semi-arid Brazil have been reported as important sites supporting a diverse fish fauna. As such, they must be able to trophically sustain fish species that feed at different trophic levels. This study aims to describe the diets of Astyanax aff. bimaculatus, Hoplias malabaricus and Prochilodus brevis in aquatic systems in semiarid Brazil, providing evidence of the importance of these habitats as supporters of large consumers like fish. The diet of the three species studied was diverse, feeding on a range of food items, from microalgae to fish. Despite that, a few items were more important to each of the study species. These results and the relatively high rates of stomach fullness indicate that a diverse and abundant food range is available in the study sites, but species seem to select some food resources. The present study provides evidence that despite being highly variable, intermittent and semi-permanent aquatic systems in semi-arid Brazil are able to trophically sustain large consumers.