scholarly journals Diet and trophic structure of the fish fauna in a subtropical ecosystem: impoundment effects

2013 ◽  
Vol 11 (4) ◽  
pp. 891-904 ◽  
Author(s):  
Rosilene Luciana Delariva ◽  
Norma Segatti Hahn ◽  
Elaine Antoniassi Luiz Kashiwaqui
Keyword(s):  
Trophic Structure ◽  
Feeding Habits ◽  
Spatial Scales ◽  
Fish Fauna ◽  
Stomach Contents ◽  
Trophic Guilds ◽  
Before And After ◽  
Temporal And Spatial ◽  
Nmds Analysis ◽  
Iguaçu River

This study examined the diet and trophic structure of the fish fauna, over temporal and spatial scales, as affected by the impoundment of the Iguaçu River in the region of Salto Caxias, Paraná State, Brazil. Sampling was conducted before (March 1997 - February 1998) and after the impoundment (March 1999 - February 2000), at four sampling sites. The stomach contents were analyzed by the volumetric method. The species could be organized in 10 trophic guilds: algivores, carcinophages, detritivores, herbivores, aquatic insectivores, terrestrial insectivores, invertivores, omnivores, piscivores, and planktivores; the first and last guilds were represented only in the post-impoundment period. Similarity patterns and feeding changes were summarized by a non-metric Multi-dimensional Scaling (nMDS) analysis and statistically tested by a Permutational multivariate analysis of variance (PERMANOVA). Most species showed feeding changes, except for the piscivores and detritivores. These changes were related to the temporal factor (impoundment phases), such as reduced intake of benthic organisms and allochthonous food, which were usually replaced by resources from the reservoir itself (algae, microcrustaceans, and fish), simplifying the food spectrum of the fish fauna. A different indicator of food resources (IndVal) corroborated these changes in the feeding of the species. The proportions of the trophic guilds evaluated based on the catch per unit of effort (CPUE) and tested by ANOSIM were significantly different before and after the impoundment. Herbivores and piscivores were the guilds that contributed (SIMPER) to these differences, especially the high increase in biomass of the piscivore guild after the impoundment. Variations in the abundance of trophic guilds were more directly related to changes in the feeding habits of the fish fauna than to increases in the number and biomass of the species that constitute these guilds.

scholarly journals Food spectrum and trophic structure of the ichthyofauna of Corumbá reservoir, Paraná river Basin, Brazil

2006 ◽  
Vol 4 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Karla D. G. Luz-Agostinho ◽  
Luis M. Bini ◽  
Rosemara Fugi ◽  
Angelo A. Agostinho ◽  
Horácio F. Júlio Jr.
Keyword(s):  
Fish Species ◽  
Trophic Structure ◽  
Environmental Changes ◽  
Stomach Contents ◽  
Trophic Groups ◽  
Trophic Plasticity ◽  
Before And After ◽  
Ordination Method ◽  
Temporal And Spatial ◽  
Terrestrial Insects

In this paper we evaluate plasticity of fish concerning diet. We expect that sampling over a large temporal and spatial scale, including environmental changes such as impoundments, will allow us to cover most of the diet plasticity. We also evaluate the efficacy of ordination method in discriminating trophic groups based on fish species diet. Data were obtained from 17 sampling stations sampled monthly from March/96 to February/99 in the Corumbá river drainage, before and after the formation of the Corumba reservoir. Diet was determined analysing 9,177 stomach contents from 64 fish species. Trophic categories were discriminated by a non-hierarchic grouping analysis named k-means, applied to diet data. Most of the species presented great trophic plasticity, eating a great variety of food items. Resources availability, estimated from all fish stomach contents, was similar among environments, except in creeks, where it varied more with a large importance of terrestrial insects. K-means present satisfactory results, identifying nine trophic groups (detritivores, herbivore-piscivores, insectivore-herbivores, omnivores, invertivores, aquatic insectivores, piscivore-insectivores, piscivores and herbivores).

scholarly journals Ichthyofauna of streams from the lower Iguaçu River basin, Paraná State, Brazil

2016 ◽  
Vol 16 (3) ◽  
Author(s):  
Crislei Larentis ◽  
Rosilene Luciana Delariva ◽  
Louise Cristina Gomes ◽  
Dirceu Baumgartner ◽  
Igor Paiva Ramos ◽  
...  
Keyword(s):  
River Basin ◽  
Fish Fauna ◽  
Main Channel ◽  
Indicator Species Analysis ◽  
Irreversible Loss ◽  
Species Analysis ◽  
Geomorphological Processes ◽  
Nmds Analysis ◽  
Iguaçu River

Abstract The drainages of the Iguaçu River basin, as well as the main channel of the river, have peculiar characteristics resulting from geomorphological processes in this area, including the formation of the Iguaçu River Falls. This slope in the lower portion of the basin is a biogeographical barrier to many organisms. In this study was inventoried the fish fauna of streams of the lower Iguaçu River basin, evaluating possible differences in the species composition upstream and downstream of this biogeographical barrier. Sampling were conducted between 2004 and 2013, in five streams, three upstream and two downstream of the Iguaçu River Falls, using electrofishing. The nMDS analysis was run to investigate possible groupings of similar fauna between the streams sampled. The scores of this test were tested as to the significance of groupings with the Hotelling T2 test. The indicator value method (IndVal) was used to detect the distribution of species among the groups of the streams upstream and downstream of the Iguaçu River Falls. We collected 18,908 individuals of six orders, 11 families, and 40 species. Siluriformes and Characiformes had the highest species richness; Cyprinodontiformes presented the highest abundance. Considering the species recorded, 21 are considered natives to the Iguaçu River basin, including 15 endemic, wich were found only in streams upstream of the falls. Additional 18 species were verified only in the streams downstream of such barrier. Four species were common to both stretches. The axis 1 of the nMDS separated two groups: streams upstream (S1, S2 and S3) and streams downstream of the Iguaçu River Falls (S4 and S5). The indicator species analysis also indicated a distinction between the groups of streams, that were significantly different (Hotelling's T2 = 234.36, p ˂ 0.0001). The number of endemic species in the streams upstream of the Falls (15 spp.) evidences a significant effect of isolation promoted by the Iguaçu River Falls, and confirms the role of this barrier in the vicariant processes and endemism typical of this basin. These results emphasize the importance of conserving these ecosystems, once the extinction of species in this region means the irreversible loss of them.

scholarly journals Do environmental variables predict the trophic structure of fish fauna in a subtropical river (Uruguay River Ecoregion)?

2018 ◽  
Vol 77 (2) ◽  
Author(s):  
Mayara P. Neves ◽  
Dirceu Baumgartner ◽  
Gilmar Baumgartner ◽  
Rosilene L. Delariva
Keyword(s):  
Environmental Variables ◽  
Trophic Structure ◽  
Fish Fauna ◽  
Environmental Parameters ◽  
Inorganic Phosphorus ◽  
Trophic Guilds ◽  
River Continuum ◽  
Environmental Filters ◽  
Energy Flows ◽  
Numerical Abundance

Trophic interactions represent the routes through which energy flows upwards within ecosystems and the understanding of such structuring under varying environmental conditions is still challenging. Here we test the hypothesis that differences in environmental variables act as environmental filters on the composition and trophic structure of local the fish fauna of a subtropical mountain river. We predict that differences in the trophic structure of the fish fauna occur along the river continuum. Main environmental parameters have been measured and fishes were sampled quarterly between August 2013 and May 2014 at six sampling sites in the main channel of the Pelotas River, Upper Uruguay ecoregion. We collected 3848 individuals belonging to 38 species, 4 orders and 11 families. The most (82.1%) consisted of small- and medium-sized individuals. The species were classified into eight trophic guilds: aquatic insectivorous, carnivorous, detritivorous, detritivorous/aquatic insectivorous, herbivorous, iliophagous, omnivorous and piscivorous. In general, herbivorous and piscivorous guilds were the most representative in both number and biomass. Significant differences detected by Permanova were for richness, numerical abundance and biomass between all the sites sampled. Relationships between the environmental variables and the composition of trophic guilds were observed along the longitudinal gradient by RLQ and fourth-corner analyses. The abundance of guilds omnivorous, aquatic insectivorous and herbivorous increases with higher values of chlorophyll-a and vegetation cover, especially characterizing the upstream sites (S1, S2 and S3). On the other hand, the abundance of the iliophagous, detritivorous/insectivorous and piscivorous guilds increases with greater values of width, temperature, inorganic phosphorus and total solids, a fact observed in downstream sites (S4, S5 and S6). Thus, it was possible to identify a clear variation in the trophic structure of the fish fauna along the Pelotas River (upstream-downstream), in which the local variables were efficient in predicting environmental filters that influence the trophic organization. In this scenario, our study follows the longitudinal model and evidences a greater accumulation of energy in food webs in the upstream-downstream direction, which favors the greatest abundance of piscivorous, detritivorous and iliophagous verified in stretches of greater volume and dimensions of river. These results highlight the importance of the local variables and the interrelationships in the lateral connectivity processes along the river continuum.

scholarly journals Diet of a catfish before and after damming of the salto caxias reservoir, iguaçu river

2007 ◽  
Vol 50 (5) ◽  
pp. 767-775 ◽  
Author(s):  
Rosilene Luciana Delariva ◽  
Norma Segatti Hahn ◽  
Luiz Carlos Gomes
Keyword(s):  
Significant Interaction ◽  
Life Stage ◽  
Stomach Contents ◽  
Detrended Correspondence Analysis ◽  
Diet Shift ◽  
Ontogenetic Diet Shift ◽  
Species Analysis ◽  
Before And After ◽  
High Degree ◽  
Iguaçu River

This study evaluated the diet of Pimelodus sp., before and after damming of Salto Caxias, (waterfall in the Iguaçu river), as well spatial and ontogenetic diet shift. Surveys were carried out from March 1997 to February 1998 (before damming) and from April 1999 to January 2000 (after damming) inside the reservoir and adjacent tributaries. Stomach contents analysis of 682 specimens revealed omnivory with high degree of trophic opportunism to this species. Analysis of variance (three way ANOVA) for scores produced from Detrended Correspondence Analysis (DCA) yielded a significant interaction between the damming phases and size of the individuals (juveniles and adults) (F = 4.68; P = 0.04). After damming, adults exploited mainly fish, whereas the juveniles fed mostly on plants, dipterans larvae and scales at different sites. From significant differences in the ordination among the factors considered, it could be inferred that the diet of Pimelodus sp. was influenced by the formation of the reservoir and this depended on the life stage considered. Position of the sites (feeding grounds) did not lead to significant alterations in diet.

scholarly journals Differences in ichthyofauna feeding habits among lateral lagoons and the river channel in a large reservoir

2015 ◽  
Vol 75 (2) ◽  
pp. 380-390 ◽  
Author(s):  
M. Ferrareze ◽  
MG. Nogueira ◽  
L. Casatti
Keyword(s):  
Aquatic Insects ◽  
Feeding Habits ◽  
Sampling Site ◽  
Fish Fauna ◽  
Stomach Contents ◽  
Niche Overlap ◽  
River Channel ◽  
Trophic Specialization ◽  
Dietary Specialization ◽  
Large Reservoir

In this study, we investigated differences in feeding habits of small-sized ichthyofauna among lateral lagoons and the river channel in a large reservoir. The study was performed in four lagoons and in one sampling site of the main channel in Rosana Reservoir, Paranapanema River, Brazil. The samples were taken in September and November of 2004 and in January, March, May, and August of 2005. Fish were sampled with a 7.5 m2 hand net. Five manual throws were made toward aquatic macrophytes stands. The sampling design favored the collection of small-sized fish fauna (juveniles/small-sized species). The stomach contents of 42 species were analyzed. A total of 183 different items were consumed by fish. These items were grouped in 11 food categories, which were used to classify fish into seven trophic guilds. Aquatic insects were consumed by 32 species and were the predominant feeding item. In the river, the most consumed items were aquatic insects, cladocerans, and phytoplankton, whereas in the lagoons aquatic insects, copepods, and cladocerans were the main items. By comparing each trophic guild, the number of insectivores, algivores, and zooplanktivores species was higher in the lagoons than in the river, and the opposite was found only for omnivore fish. Low niche width in all sites indicates high trophic specialization and low niche overlap between pairs of species. Fish assemblage in the lateral lagoons presents feeding habits distinct from those of the river species, indicating that the coexistence and high abundance of small-sized fish in the sampling sites are explained by their high feeding adaptability, which includes a tendency toward dietary specialization, low feeding overlap, and resource partitioning, along with different temporal resource uses.

scholarly journals On the diet of two endemic and rare species of Trichomycterus (Ostariophysi: Trichomycteridae) in the Jordão River, Iguaçu River basin, southern Brazil

2013 ◽  
Vol 35 (84) ◽  
Author(s):  
Almir Petersen Barreto ◽  
Fabiane Cristina Armiliato ◽  
Vanessa Maria Ribeiro ◽  
Vinícius Abilhoa
Keyword(s):  
River Basin ◽  
Diet Composition ◽  
Feeding Habits ◽  
Monitoring Program ◽  
Stomach Contents ◽  
Scaling Analysis ◽  
Multidimensional Scaling Analysis ◽  
Organic Detritus ◽  
Energetic Complex ◽  
Iguaçu River

The diet and the eect of body size on the feeding habits of Trichomycterus crassicaudatus and Trichomycterus stawiarski, collected in the Jordão River, an import tributary of the Iguaçu River basin, were investigated. Samples were collected in august 2003 during the Jordão River Energetic Complex Aquatic Fauna Rescue and Monitoring program. Stomach contents were evaluated through the frequency of occurrence, permutational multivariate analysis of variance (PERMANOVA), si-milarity percentage analysis (SIMPER) and non-metric multidimensional scaling analysis (MDS) methods. A total of 86 stomach contents of T. stawiarski and 36 of T. crassicaudatus were assessed. The species presented an insectivorous feeding habit, with differences in the diet composition of the “smallest” and the “largest” individuals. Ephemeroptera nymphs, lar-vae and pupae of Diptera, organic detritus and plant fragments were the most important food items. Both species feeding habits were based mainly in benthic aquatic immature insects.

scholarly journals Food resources sustaining the fish fauna in a section of the upper São Francisco River in Três Marias, MG, Brazil

2004 ◽  
Vol 64 (2) ◽  
pp. 195-202 ◽  
Author(s):  
M. C. C. Alvim ◽  
A. C. Peret
Keyword(s):  
Aquatic Invertebrates ◽  
Fish Fauna ◽  
Stomach Contents ◽  
Food Resources ◽  
Trophic Guilds ◽  
Terrestrial Invertebrates ◽  
Sao Francisco River ◽  
Seasonal Flooding ◽  
São Francisco River

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.

scholarly journals Use of food resources by the fish fauna of a small reservoir (rio Jordão, Brazil) before and shortly after its filling

2006 ◽  
Vol 4 (3) ◽  
pp. 357-362 ◽  
Author(s):  
Valdirene E. Loureiro-Crippa ◽  
Norma S. Hahn
Keyword(s):  
Food Supply ◽  
Fish Fauna ◽  
Stomach Contents ◽  
Detrended Correspondence Analysis ◽  
Food Resources ◽  
Limiting Factor ◽  
Trophic Groups ◽  
Small Reservoir ◽  
Risk Of Extinction ◽  
Before And After

The construction of dams brings about changes in the course of a river, which directly or indirectly affect the fish fauna. Alterations in the food resources available to the fish favor some species and deter others. In addition to the implications originating from damming, Jordão Reservoir has a characteristically large number of endemic species that, because of the impacts they have undergone, run the risk of extinction. In this study, we investigate the feeding flexibility of the fishes faced with alterations in the food supply through the assessment of the diet and trophic organization of the fish fauna (before and after the damming). Diet was determined analyzing 1,861 stomach contents from 27 fish species. Eight of this species were not caught after the damming. Detrended Correspondence Analysis (DCA) discriminated seven trophic groups. Omnivorous, insectivorous and invertivorous species had more temporal alterations in their diets. These changes altered the composition (in abundance and biomass) of the trophic groups, mainly after the damming. The detritivorous and piscivorous species maintained their diets during all study period. Analyses showed that about 75% of the species quickly changed their diets according to alterations in food supply. This implies that food is not a limiting factor (at first) for the maintenance of fish fauna of this reservoir, at least for the species that persisted after the filling.

scholarly journals Trophic structure of fish fauna along the longitudinal gradient of a first-order rural stream

2015 ◽  
Vol 27 (4) ◽  
pp. 381-393 ◽  
Author(s):  
Jardel Nimet ◽  
Rosilene Luciana Delariva ◽  
Luciano Lazzarini Wolff ◽  
Jislaine Cristina da Silva
Keyword(s):  
Multidimensional Scaling ◽  
Trophic Structure ◽  
Environmental Gradients ◽  
Fish Fauna ◽  
Trophic Niche ◽  
Trophic Guilds ◽  
Longitudinal Gradient ◽  
First Order ◽  
Metric Multidimensional Scaling ◽  
Longitudinal Variations

Abstract Aim: This study evaluated the trophic structure of the fish assemblage along the longitudinal gradient of a first-order rural stream. Methods Fish were sampled by electrofishing technique in December 2007, September 2008 and March 2009, at three stretch of the Itiz stream (headwater, middle and mouth). We sampled 1,255 individuals relating to 18 species. The categorization of trophic guilds was based on stomach content data of 1,096 individuals, analyzed according to the volumetric method, except for four species, which were classified according to the literature. To test the hypothesis of differences in the richness, abundance and biomass of trophic guilds along the headwater-mouth gradient, it was performed non-parametric statistical analysis of the dietary data. Was also calculated, the amplitude of trophic niche (Levins's index) for each guild. To summarize the composition and abundance of the trophic guilds along the longitudinal gradient, we applied a non-metric multidimensional scaling (NMDS). Results We registered seven guilds: herbivorous, detritivorous, aquatic insectivorous, terrestrial insectivorous, invertivorous, omnivorous and piscivorous, the latter was exclusive to headwater and middle stretches. The omnivorous guild was not recorded in the headwater. Through PERMANOVA analysis it was found that the species richness of more specialized guilds (detritivorous and insectivorous terrestrial) and of generalist invertivorous increased, while less specialized guilds like aquatic insectivorous and herbivorous, decrease significantly in headwater-mouth direction. Except by the non-expected increase of insectivorous terrestrial and decrease of herbivorous downstream, the non-metric multidimensional scaling (NMDS) identified longitudinal variations in abundance and biomass of the guilds that agree with general patterns of fish guilds distribution along environmental gradients. Conclusion These results suggest that the influence of environmental conditions around the stream (local particularities) also contributed to the formation of the observed patterns of trophic guilds along its longitudinal gradient.

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