Genotoxicity biomarkers on native fish species from the Araguari River (Amazon biome).

The Araguari River, one of the most important waterways in the Brazilian state of Amapá, is ecologically relevant and essential for the conservation of Amazonian fish biodiversity. Our previous studies demonstrated contamination of water and fish by metals. In particular, water samples showed genotoxic damage in Danio rerio. Here, we extended our studies of potential genotoxic damage to native fish from sampling sites located in the Araguari River lower section. To accomplish this, we collected samples of fish with different feeding behaviors, but in the same sampling sites, and evaluated the same genotoxicity biomarkers in erythrocytes. All eleven species of fish collected in the Araguari River lower section showed profiles and frequencies of genotoxic damage similar to those previously observed in tests with D. rerio, confirming that genotoxic pollutants present in these waters are also causing damage to native fish species.

Metal bioaccumulation in fish from the Araguari River (Amazon biome) and human health risks from fish consumption.

Recently, high concentrations of metals have been found in the waters from sampling sites located in the Araguari River lower section. These metals can be bioaccumulated by fish, but also biomagnified, representing a potential risk through human consumption. Here, we aimed to (1) determine the metal concentrations in muscle samples from fish; (2) evaluate bioaccumulation of metals in muscle tissue of fish species with different feeding behaviors; and (3) investigate the risks of single metals, as well as mixture of metals, to human fish consumption. Eleven fish species were sampled (3 carnivorous, 5 omnivorous, and 3 detritivorous). In four fish species, Cd and Pb concentrations exceeded the Brazilian maximum limits (MLs) for human consumption. Individually, Pb and Cd concentrations in the muscle of these fish indicate risks to human health. When considering the mixture of metals, the consumption of all fish species represents risks. The highest risks implicate detritivorous species. For all fish species evaluated, the estimated daily intake (EDI) of Hg shows values above its reference dose (RfD). Our results suggest the need to establish an environmental monitoring program that aims to preserve environmental quality, biodiversity, and human health. It is also necessary to develop actions that aim to educate Amazonian populations on safe fish preparation and consumption.

Bioaccumulation, genotoxicity, and risks to native fish species from inorganic contaminants in the Pantanal Sul-Mato-Grossense, Brazil.

The Aquidauana River is one of the most important rivers in the Pantanal region, Brazil. However, its waters have been contaminated by nearby anthropogenic activities, threatening native fish species. In this study, our objectives were: 1) to determine the concentrations of Al, As, Cd, Cu, Fe, Mn, Ni, Pb, and Zn in water and sediment samples from the Aquidauana River and to assess the risks posed to aquatic biota; 2) to quantify the concentration of these elements in muscle and liver tissue samples from four native fish species; 3) to evaluate the potential bioaccumulation of inorganic elements in the muscles and liver; and 4) to investigate genotoxicity biomarkers and their association with the inorganic element concentrations present in the muscle tissue. Water and fish samples were collected in November 2020. The concentrations of Al, As, Cd, Cu, Fe, and Pb in the water samples were in disagreement with the Brazilian legislation and presented risks to the aquatic biota. In terms of mixtures of inorganic elements, there was a great increase in the risk to biota. The As concentration did not meet the Brazilian standard for sediments in the sample collected at sampling site 6. The concentrations of Cd and Pb in the muscle tissue of Hypostomus regani, Prochilodus lineatus, Brycon hilarii, and Mylossoma duriventre exceeded the Brazilian standards for human consumption. H. regani showed greater genotoxic damage, and the higher the Al and Fe concentrations in the muscle tissue, the higher the frequencies of lobulated nuclei and nuclear invaginations. Together, our results demonstrate the negative impacts on native fish species from the Aquidauana River contamination and indicate risks to Pantanal biodiversity.

Landscape composition and inorganic contaminants in water and muscle tissue of Plagioscion squamosissimus in the Araguari River (Amazon, Brazil).

Amazonian aquatic environments are seriously impacted by dam-building and deforestation, among other threats. Therefore, the present study aimed to examine water quality in the middle and lower course of the Araguari River with respect to the composition of vegetative cover and the concentration of As, Cd and Hg in order to determine risks to the preservation of biota and risks to human health from consumption of P. squamosissimus contaminated with these inorganic elements. To accomplish this, water samples and fish specimens were collected in the middle and lower Araguari River in 2019. The concentration of inorganic contaminants was analyzed by atomic absorption spectrophotometry. These stretches of the Araguari River presented higher proportions of forest fragments and evident expansion of buffalo pastures. According to Brazilian legislation, the concentrations of Cd and Hg in the water samples represented risk quotient values > 1, indicating risk to the preservation of aquatic biota. In particular, the concentrations of Cd in the muscle tissue of P. squamosissimus in the lower Araguari River also indicated risks to human health. The bioaccumulation factor indicated that Hg is bioavailable in the water. It can be concluded that water imbalances in the middle and lower Araguari River compromise the health of both aquatic and human life.

Acute Toxic and Genotoxic Effects of Aluminum and Manganese Using In Vitro Models.

The objective of this study was to use the same concentrations of aluminum (Al) and manganese (Mn) detected previously in groundwater above those permitted by Brazilian law and assess their cytotoxic and genotoxic effects in hamster ovary cell lines and their mutagenic effects through the Salmonella microsome assay. Chinese hamster ovary (CHO) and CHO-XRS5 cells were treated with different concentrations of Al and Mn (0.2 to 2.0 mg/L and 0.1 to 3.0 mg/L, respectively). The Ames test was used to analyze the concentrations of Al and Mn ranging from 0.025 to 1.0 mg/L and 0.0125 to 1.5 mg/L, respectively. Both metals showed cytotoxic effects on both cell lines and two bacterial strains (TA98 and TA100). The genotoxic effects of the highest concentrations of Al and Mn in cell lines showed nuclear buds, micronuclei, and DNA damage; however, none of the concentrations showed a positive mutagenic response in the Ames test. This is one of the few studies to demonstrate the cytotoxic effects of Al and Mn through the Ames test. In addition, the metals caused genomic instability in cell lines. Therefore, this study may help hasten the review of established regulatory standards for human consumption of groundwater.

High concentrations of metals in the waters from Araguari River lower section (Amazon biome): Relationship with land use and cover, ecotoxicological effects and risks to aquatic biota.

The Araguari River is one of the most important water body in the Brazilian state of Amapá. However, the quality of its waters has been deteriorating and, recently, high concentrations of metals were found in water samples collected from its lower section. Overall, we aimed to evaluate land use and cover around three sampling sites located in the Araguari River lower section and its contribution to water pollution by metals; correlate land use pattern with detected metal concentrations; assess acute toxicity using the Daphnia similis test and genotoxicity using the Danio rerio bioassay of water samples from the three sampling sites; and investigate the risks arising from metals present in waters to aquatic biota. Riparian forest around all sampling sites is fragmented owing to the expansion of pasture areas, which showed a significant positive correlation (p < 0.05) with the concentrations of Hg and Cu in water samples. Water samples from sampling sites 2 and 3 presented acute toxicity for D. similis, and the D. rerio bioassay confirmed the presence of genotoxic pollutants in the waters from all sampling sites. Our preliminary risk assessment showed that individual concentrations and the mixture of metals posed a high risk to aquatic biota. Taken together, our results demonstrate that the conversion of native forest to pastureland contributes to water contamination by metals, which contributes to the risks to aquatic biota.

Toxicogenetic effects on fish species in two sub-basins of the upper Paraguay river, Southern Pantanal - Brazil.

This study aimed to evaluate water quality using limnological parameters in two sub-basins of the Negro and Apa Rivers, along with the composition and structure of the landscape around the locations sampled in the two sub-basins and their possible contribution to the loss of water quality. We also set out to identify the genotoxic effects on the erythrocytes of Prochilodus lineatus and Leporinus friderici. In particular, we quantified total Cr, Ni and Pb in the muscle of these fish species to determine which genotoxic changes are related to the concentration of metals detected in the fish from these two sub-basins of the Paraguay River Basin. The sub-basin of the Apa River presented a greater proportion of surrounding pastureland in relation to the basin of the Negro River. The erythrocytes of P. lineatus showed a significant difference between the sub-basins for nuclear pyknosis, binucleated cells and lobed nuclei (p < 0.05). In L. friderici, vacuolated nuclei, nuclear pyknosis and lobed nuclei alterations also showed a significant difference between the sub-basins (p < 0.05). The genotoxicity index of the Apa River sub-basin presented higher frequencies of nuclear alterations in P. lineatus and L. friderici (p < 0.05), compared to the Negro River sub-basin. The concentration of total Cr, Ni and Pb in the muscles of P. lineatus and L. friderici in the Negro River sub-basin leads to genotoxic damage, mainly from the induction of lobed nuclei. Based on our results, it can be concluded that toxicogenetic effects in native fish species are an important source of environmental diagnosis in the Upper Paraguay River Basin.

Bioaccumulation of metal in liver tissue of fish in response to water toxicity of the Araguari-Amazon River, Brazil.

This study aimed to determine the concentration of metals in the water and in the liver tissue of fish (Anodus orinocensis, Hemiodus unimaculatus, Curimata vittata, and Plagioscion squamosissimus) in the lower Araguari River. Steps were also taken to estimate any difference in metal bioaccumulation in the liver of fish species at different trophic levels, determine any correlations between metals found in hepatic tissue of fish species relative to that found in river water, and evaluate the bioaccumulation factor. The metals analyzed in the water in the lower Araguari River (Cd, Pb, Fe, Hg, Cu, and Zn) exceeded the limits considered safe for aquatic life. We found a significant difference only in the bioaccumulation of Pb between A. orinocensis and C. vittata (F = 4.65, p = 0.005) and Cr between A. orinocensis and H. unimaculatus (F = 3.12, p = 0.03). Species of distinct trophic levels showed differences in metal concentration in liver. Cd and Cu showed bioaccumulation factor above 100, especially Cu with a relatively high value, for all fish species. The bioaccumulation of metals in the liver of fish species showed a positive correlation with the metals detected in the water of the Araguari River. In this sense, the lower course of the Araguari River is undergoing some type of environmental stress, making this study of additional valuable in diagnosing environmental quality pursuant to the development of environmental monitoring projects in order to guarantee the safety and maintenance of aquatic life.

Evaluation of the water quality in a conservation unit in Central-West Brazil: Metals concentrations and genotoxicity in situ.

This study assessed the quality of vegetation cover in the Parque Estadual das Várzeas do Rio Ivinhema (PEVRI, Upper Paraná River basin, MS, Brazil), the concentration of metals (Cd, Pb, Cr, Cu, Fe, Zn and Ni) in water and muscle and hepatic tissues of five fish species collected in the PEVRI - Hemiodus orthonops, Leporinus friderici, Prochilodus lineatus, Pterodoras granulosus and Pimelodus maculatus - in addition to non-carcinogenic risk assessment and genotoxicity potential in these species. Regarding vegetation index, we found that only 26.25% of the PEVRI area is occupied by denser vegetation. In the sites analyzed, Cd, Cu, Fe and Ni showed high concentrations in water, above the reference values established by the legislation. In the muscle and hepatic tissues of the fish species analyzed, Cd and Pb values exceeded the reference limits. The genotoxic alterations identified in erythrocytes of the fish species studied were nuclear invagination, nuclear budding, picnosis, binucleated cell and lobulate nucleus. For the non-carcinogenic risk assessment in fish, Cd and Pb presented values greater than 1, indicating risk in the consumption of these fish. In the bioaccumulation factor, Cd and Pb were greater than 100 in all fish species analyzed, except for Pb in L. friderici. The results indicated that the water resources of the PEVRI are being affected by some type of contaminant, probably due to anthropic activities carried out around the park or carried from the upper portions of the basin through the drainage system.

Effects of age, sex, medication, and environmental conditions on genetic alterations in oral mucosa cells.

In the present study, we evaluated the effects of biological factors, lifestyle factors, and environmental conditions on the induction of DNA damage in exfoliated cells of the oral mucosa. Age, sex, medication use, and environmental conditions were analyzed in individuals residing in the cities of Caarapó and Itaporã. The individuals were assessed by a questionnaire, and oral mucosa cells were collected and subjected to mutagenicity analysis. We observed no statistical differences in DNA damage related to sex. However, the mutagenic effect was found to be proportional to age, with higher frequencies of DNA damage observed in individuals between the ages of 46 and 65 years. In addition, higher frequencies of DNA damage were found in individuals who continuously used medication and for prolonged periods, and greater DNA damage was observed in individuals who used antihypertensive drugs than those who took antidepressants. In terms of environmental conditions, Caarapó residents had a significantly higher frequency of DNA damage than that of residents from Itaporã. Based on the analysis of land use and occupation, this result can be attributed to the smaller fraction of forest fragments and the higher proportion of buildings in Caarapó than Itaporã. We concluded that age, continued medication use, and environmental conditions can lead to greater DNA damage.

Use of fish scales in environmental monitoring by the application of Laser-Induced Breakdown Spectroscopy (LIBS).

The objective of this study was to evaluate the efficiency of Laser-Induced Breakdown Spectroscopy (LIBS) to detect the presence of bioaccumulated Fe and Pb in scales of Salminus brasiliensis and Prochilodus lineatus, and to compare the results from this technique with those obtained using the conventional atomic absorption spectrometry technique. The study used fish collected in the Amambai River, Upper Paraná River, Brazil. The LIBS technique detected the presence of Fe in S. brasiliensis scales and Fe and Pb in P. lineatus scales on different regions. Using atomic absorption spectrometry, we verified a significant difference in Fe concentration in scales between the species analyzed, with a higher concentration in S. brasiliensis than in P. lineatus (p = 0.0004). Pb was not detected using atomic absorption spectrometry in either species because the concentration of this element was below the limit of detection of this technique. The LIBS technique was efficient in detecting Fe and Pb in scales of the two species analyzed, proving to be a promising tool for environmental monitoring.

Influence of Land Use and Cover on Toxicogenetic Potential of Surface Water from Central-West Brazilian Rivers.

The objective of this study was to evaluate toxicogenetic potential of surface water samples from rivers of center-west Brazil and analyze the influence of land use and cover and physicochemical parameters in genetic damage. Samples were collected during winter (June) and summer (November) at sampling sites from Dourados and Brilhante Rivers (Mato Grosso do Sul/Brazil). The toxicogenetic variables, including chromosomal alterations, micronuclei, and mitotic index, were analyzed in meristematic cells of Allium cepa; and micronuclei, nuclear abnormalities, and DNA strand breaks (arbitrary units, AUT) were analyzed in erythrocytes of Astyanax lacustris. The rivers presented physicochemical values outside the Brazilian laws, which can be a characteristic of human pollution (domestic sewage and local agriculture). The results of A. cepa test suggest that the water samples from Dourados and Brilhante rivers exerted significant (p < 0.05) cytotoxic and genotoxic effects, in both periods of collection, especially alterations in mitotic index. In blood cells of A. lacustris, genotoxic effect of the water samples from the rivers also was observed as significant nuclear abnormalities, DNA breaks (UAT), in both sampling periods, compared with the negative control. Spearman correlation analyses revealed that data of land use and cover and physicochemical parameters were statistically correlated with DNA damages in bioassays. This study demonstrates toxicogenetic potential of water samples from Dourados and Brilhante rivers; furthermore, the type of land use and land cover and physicochemical parameters were revealed to have influence on toxicogenetic damage.

From collection to discharge: physical, chemical, and biological analyses for fish farm water quality monitoring.

The use of chemical substances for the management of fish farming activities may compromise the quality of the tank water itself and of water bodies that receive the effluents. As studies that assess the environmental effect caused by pisciculture are scarce, the present study aimed at evaluating the water quality in two fish farms in the region of Grande Dourados, Brazil, from the site of water collection to the site of water disposal. The tools used for this purpose were the analysis of land use and cover and the determination of physical, chemical, and biological parameters of water samples. Maps of land use and cover were created, and water samples were collected at four sampling sites in two fish farms. The Allium cepa test, assays with Astyanax lacustris, and the Salmonella/microsome assay were performed. In addition, physical and chemical parameters were measured and metal and emerging contaminants in the water samples were investigated. The A. lacustris demonstrated the genotoxicity and the Salmonella/microsome assay suggested the mutagenic potential of water samples from the fish farms and indicated higher genotoxicity in the disposal tanks than in the collection tanks of the Brilhante fish farm. However, all the samples at the Dourados fish farm were genotoxic, and mutagenicity was shown to start at the water collection site. With regard to the A. cepa test, there was no statistical difference between the collection sites in both fish farms. Moreover, the observed genetic damage may be associated with the presence of metals and emerging contaminants in the water samples, which suggests that these chemicals have potential genotoxic and mutagenic effects that are related to the type of land use and cover in the area of the region studied. Considering that contaminated waters can potentially disturb the structure and functioning of natural ecosystems, the present study demonstrated the importance of treating fish farm effluent to minimize the negative effect of this activity on water bodies.

Toxicological properties of an aqueous extract of Aristolochia triangularis leaves, using the brine shrimp lethality and Allium cepa bioassays / Propriedades toxicológicas de um extrato aquoso de folhas de Aristolochia triangularis utilizando os bioensaios de letalidade com Artemia salina e Allium cepa

ABSTRACT: The aqueous extract of Aristolochia triangularis leaves showed activity against Artemia salina larvae, with an LD50 of 370.6 µg/mL. In experiments with Allium cepa seeds, the extract caused a 51.26% reduction in the germination index, inhibited mean root growth, and was cytotoxic at concentrations of 668 and 2,000 µg/mL. Its antioxidant activity was additionally assessed in this research and the ferric reducing antioxidant power value was found to be 391.2 µM/g. Such health-beneficial property can be attributed partly to the total phenolic content, spectrophotometrically determined as 52.67 mg/g. The occurrence of cytotoxicity suggested caution when consuming teas from A. triangularis leaves for medicinal purposes, and equally reveals the need for further studies to investigate their adverse effects.

RESUMO: O extrato aquoso de folhas de Aristolochia triangularis mostrou atividade sobre larvas de Artemia salina, com um DL50 de 370,6 µg/mL. Em experimentos com sementes de Allium cepa, o extrato provocou uma redução de 51,26% no índice de germinação, inibiu o crescimento radicular médio e foi citotóxico nas concentrações de 668 e 2.000 µg/mL. Sua atividade antioxidante foi adicionalmente avaliada nesta pesquisa e o valor de poder redutor de íons férrico foi de 391,2 µM/g. Tal propriedade benéfica para a saúde pode ser parcialmente atribuída ao conteúdo de compostos fenólicos totais, espectrofotometricamente determinada como 52,67 mg/g. A ocorrência de citotoxicidade sugeriu cautela ao consumir chás de folhas de A. triangularis para propósitos medicinais, e igualmente revela a necessidade por estudos adicionais para investigar os efeitos adversos deles.

The Response of Neotropical Fish Species (Brazil) on the Water Pollution: Metal Bioaccumulation and Genotoxicity.

The streams and rivers of the Upper Paraná River Basin have been seriously affected by impacts of high population density around the basin area. Fishes are widely used as models to assess the health of aquatic ecosystems, being considered as bioindicators of environmental pollution. In this context, our objective was to assess the potential genotoxic and mutagenic effects of the polluted water in three native fish species (Astyanax lacustris, Hypostomus ancistroides, and Rhamdia quelen) from Tarumã Microbasin, Upper Paraná River, Brazil. We also investigated the concentration of metals in water and in fish muscle to verify bioavailability and bioaccumulation of metals. For both less impacted sites (LI) and impacted sites (IMP) of the microbasin, the concentrations of metals were above the maximum limit allowed by Brazilian legislation (Resolution CONAMA 357/2005), except for Pb, total Cr, and Cu at LI sites and total Cr at IMP sites. A. lacustris showed a higher frequency of micronuclei (MN) at IMP sites compared with LI sites (p < 0.0001). We found no significant differences in MN frequency between site classes for H. ancistroides and R. quelen (p > 0.05). There were no significant differences between site classes regarding to nuclear abnormalities in erythrocytes frequencies (p > 0.05). A. lacustris from IMP sites had higher concentrations of Pb, Cu, Fe, Zn, and Ni in muscle tissue (p < 0.05), whereas H. ancistroides from IMP sites had higher concentration of Cr, Cu, and Ni (p < 0.0001) and R. quelen showed higher concentration of Cd, Fe, and Ni at these sites (p < 0.0001). So, the chosen biomarkers are able to identify the environmental risk of the water pollution.

Erythrocyte Nuclear Abnormalities in Astyanax lacustris in Response to Landscape Characteristics in Two Neotropical Streams.

The objective of this research was to evaluate land use and occupation in the landscape surrounding two neotropical streams of the Upper Paraná River in Brazil and to investigate if the water from these streams induces erythrocyte nuclear abnormalities in Astyanax lacustris. We observed that the areas surrounding the streams are predominantly used for agricultural purposes (73.46% of the total area), followed by buildings (15.21%). Only 8.78% of the area consisted of forest fragments. We observed higher frequencies of micronuclei in erythrocytes of A. lacustris exposed to water from impacted sites (IMP) compared with less impacted sites and the negative control (NC) (p < 0.05). Analysis of nuclear alterations in A. lacrustis erythrocytes showed significant differences in the frequency of notched nuclei and nuclear pyknosis only between the NC and the IMP sites (p < 0.05). Our results indicate that water from the most impacted sites of the microbasin can induce mutagenic and genotoxic effects in A. lacustris.

Mutagenic and genotoxic effects and metal contaminations in fish of the Amambai River, Upper Paraná River, Brazil.

The present study evaluated mutagenic and genotoxic effects and metal accumulation in the liver and musculature of Pterygoplichthys ambrosetti and Prochilodus lineatus in the Amambai River, a tributary of the Upper Paraná River in Brazil. We also evaluated the potential for these fish species as environmental bioindicators and performed risk assessment for conservation purposes. We found that P. ambrosetti had a higher frequency of micronuclei compared to P. lineatus (p < 0.0001). There were no significant differences between species in other erythrocyte nuclear abnormalities (ENA) (p > 0.05). For both species, the liver contained a higher concentration of metals (Cd, Pb, Cr, Cu, Fe, Zn, and Ni) than the musculature did (p < 0.0001). Of the two species, P. ambrosetti was more suitable to evaluate mutagenic and genotoxic effects and metal accumulation in the liver and musculature, likely due to its resident behavior; hence, we highlight the potential of this species for use as an environmental bioindicator. The concentrations of non-essential metals observed in the fish confirm conditions of environmental stress in the Amambai River, possibly related to the discharge of pollutants and exacerbated by lack of native vegetation cover along the watercourse.

Influence of environmental integrity on the reproductive biology of Astyanax altiparanae Garutti & Britski, 2000 in the Ivinhema river basin / Influência da integridade ambiental na biologia reprodutiva de Astyanax altiparanae Garutti & Britski, 2000 na bacia do rio Ivinhema

In this study, it was examined the reproductive biology of Astyanax. altiparanae, in streams with different levels of environmental disturbance in the Ivinhema river basin (Mato Grosso do Sul State, Brazil). Samplings were conducted between July 2001 and November 2011, at 101 sites, using sieves, seining nets, gill nets and electrofishing. Streams were classified into three levels of environmental integrity. We analyzed 735 specimens, 410 females and 325 males. Females predominated in impacted streams and both sexes presented nearly the same pattern of length distribution in the three levels of environmental integrity. Females reached gonadal maturity with greater lengths (L50 = 55.67mm) in altered and impacted streams and had higher reproductive activity between October and December. The species showed higher Condition Factor and higher reproductive intensity in the impacted streams. Our results evidenced that in impacted sites the species exhibited a good ability to allocate a significant portion of its energy to reproduction, probably due to the greater supply of food.

Neste estudo analisamos a biologia reprodutiva de Astyanax. altiparanae em riachos com diferentes intensidades de integridade ambiental, na bacia do rio Ivinhema, (Mato Grosso do Sul, Brasil). As amostragens foram realizadas entre julho/2001 e novembro/2011, em 101 locais, utilizando peneiras, rede de arrasto, rede de espera e pesca elétrica. Os riachos foram categorizados em três níveis de integridade ambiental. Foram analisados 735 exemplares, sendo 410 fêmeas e 325 machos. Houve maior predominância de fêmeas nos riachos impactados e ambos os sexos apresentaram aproximadamente o mesmo padrão de distribuição por comprimento nos três níveis de integridade ambiental. Constatamos que as fêmeas atingiram maturidade gonadal com maiores comprimentos (L50 = 55,67 mm) nos riachos alterados e impactados apresentaram maior atividade reprodutiva entre outubro e dezembro. A espécie apresentou maior Fator de Condição e maior intensidade reprodutiva nos riachos impactados. Os resultados evidenciaram que em locais impactados a espécie demonstra boa capacidade em alocar parte significativa de sua energia à reprodução, provavelmente em decorrência da maior oferta de alimento.

Influence of environmental integrity on the feeding biology of Astyanax altiparanae Garutti & Britski, 2000 in the Ivinhema river basin / Influência da integridade ambiental na biologia alimentar de Astyanax altiparanae Garutti & Britski, 2000 na bacia do rio Ivinhema

This study aimed at analyzing the influence of different levels of environmental integrity of streams of the Ivinhema river basin (Mato Grosso do Sul State, Brazil) on the diet of A. altiparanae. Samplings were performed from July 2001 to November 2011 at 101 sites, using sieves, seining and gill nets, and electrofishing. Streams were classified into three levels of environmental integrity. We analyzed 664 stomachs with the methods of frequency of occurrence and volumetric analysis index, combined in the Importance Index (AI). The species was omnivorous, with predominance of allochthonous resources. At the least impacted sites, the most representative resource was allochthonous plant material; and in the altered sites in the rainy period the most consumed item was allochthonous arthropods. On the other hand, at the most impacted sites in the dry period there was a lower consumption of allochthonous plant material and allochthonous arthropods, compared with other levels of environmental integrity considered, with higher consumption of autochthonous arthropods. The results evidenced that in the least impacted sites there was greater contribution from allochthonous resources, probably because these environments show a more preserved riparian forest.

Este estudo teve como objetivo analisar se os diferentes níveis de integridade ambiental de riachos da bacia do rio Ivinhema (Mato Grosso do Sul, Brasil) influenciam a dieta da espécie A. altiparanae. As amostragens foram realizadas entre julho/2001 e novembro/2011, em 101 locais, utilizando peneiras, rede de arrasto, rede de espera e pesca elétrica. Os riachos foram categorizados em três níveis de integridade ambiental. Foram analisados 664 estômagos pelos métodos de frequências de ocorrência e índice de análise volumétrica, combinados no Índice de Importância Alimentar (AI). A espécie apresentou hábito alimentar onívoro, com predomínio de recursos alóctones. Nos locais menos impactados, o recurso mais representativo foi material vegetal alóctone; nos locais alterados, no período chuvoso, o item mais consumido foi artrópodes alóctones. Por outro lado, nos locais mais impactados, no período seco, houve menor consumo de material vegetal alóctone e artrópodes alóctones, em comparação aos outros níveis de integridade ambiental analisados, com maior consumo do item artrópodes autóctones. Os resultados evidenciaram que em locais menos impactados houve maior contribuição de recursos alimentares alóctones, provavelmente porque estes ambientes apresentam mata ciliar mais conservada.