The Experts below are selected from a list of 1182 Experts worldwide ranked by ideXlab platform
Ricardo Massato Takemoto - One of the best experts on this subject based on the ideXlab platform.
-
Acanthocephalans parasites of two Characiformes fishes as bioindicators of cadmium contamination in two neotropical rivers in Brazil.
The Science of the total environment, 2020Co-Authors: Gisele Silva Costa Duarte, Atsler Luana Lehun, Lucas Aparecido Rosa Leite, Nelson Consolin-filho, Sybelle Bellay, Ricardo Massato TakemotoAbstract:Abstract Studies have demonstrated the role of acanthocephalan as environmental bioindicators. The dynamics in the parasite-host relationship that define the patterns of distribution of trace metals in parasites and, in its host, are extremely variable. In addition, the neotropical region, which is a major maintainer of the biodiversity of fish and parasites, remains little explored in this subject. Therefore, our objective was to analyze and compare the concentration of Cadmium (Cd) in the tissues of Prochilodus lineatus and Serrasalmus marginatus collected from Baia and Parana rivers, as well as to assess the use of acanthocephalan as environmental bioindicators of pollution and their Cd bioaccumulation capacity. We collected 53 fish, 20 specimens of Prochilodus lineatus from Parana River and 17 from Baia River, in addition to 16 specimens of Serrasalmus marginatus from Baia River, in September 2017 and March 2018. Tissues of the fish along with their parasites were subjected a Cd concentration analysis by Atomic Absorption Spectroscopy. The results revealed that the parasites had higher concentrations than all the tissues of S. marginatus, P. lineatus from Baia River and Parana River. The high Cd concentrations in these parasites derived from their bioaccumulation capacity, because of the absorption of nutrients directly from the intestinal content of the fish through the tegument, as well as for the presence of Cd on the surface waters of Prana River floodplain. Besides that, the Coefficient of Spearman Rank Correlation showed that the infrapopulation size seems to affect Cd bioaccumulation in the parasites, smaller infrapopulations demonstrate a higher accumulation capacity compared to the larger ones. With that, we concluded that the two acanthocephalans species analyzed in this study have a good capacity for Cd accumulation, and can be used as accumulation indicators of trace-metal pollution. Accumulation indicators provide important information on the biological availability of pollutants.
-
endoparasitic fauna of Serrasalmus spp characidae serrasalminae in a neotropical floodplain
Acta Scientiarum. Biological Sciences, 2016Co-Authors: Guilherme Pomaro Casali, Ricardo Massato TakemotoAbstract:Floodplains systems present complex biodiversity and upper Parana river floodplain retains a wide variety of terrestrial and aquatic species. Serrasalmus marginatus (nonindigenous species) and Serrasalmus maculatus (native species) are part of this biodiversity component and can be infected by trophic transmission. In order to understand the ecological processes within the upper Parana river floodplain, endoparasite fauna of those two hosts species were analyzed, considering prevalence, abundance, intensity and richness variables to determine this relationship. So, abundance of acantocephalan Echinorhynchus sp. was positively correlated to S. marginatus length, while Kritskyia annakohnae (Monogenea) prevalence and S. marginatus length presented a negative correlation. S. marginatus relative condition factor (Kn) was negatively and significantly associated to the abundance of K. annakohnae , and Kn of infected fish by that species is lower compared with the non- infected fish. Since hosts are in the context of the introducing of species, the research of endoparasites ecological variables allows to understansd infracommunity and component community as a way of analyzing the consequence of these parasites distribution in the native and non-native species.
-
Metazoan endoparasites of Serrasalmus marginatus (Characiformes: Serrasalminae) in the Negro River, Pantanal, Brazil
Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia , 2011Co-Authors: Wagner Vicentin, Ricardo Massato Takemoto, Fábio Edir Dos Santos Costa, Kelly Regina Ibarrola Vieira, Luiz E. R. Tavares, Fernando PaivaAbstract:In order to inventory the metazoan endoparasites of Serrasalmus marginatus, 91 specimens were examined. They were captured in the Negro River in Pantanal wetland, State of Mato Grosso do Sul, Central-Western Brazil, from October 2007 to August 2008. Parasites of six taxa were recovered: Procamallanus (Spirocamallanus) inopinatus, Contracaecum sp. (Nematoda), metacercarial type Diplostomulum (Digenea), Brevimulticaecum sp. (Nematoda) and Sebekia oxycephala, Subtriquetra sp. 1 and Subtriquetra sp. 2 (Pentastomida). The latter five species are reported for the first time in S. marginatus.
-
novas ocorrencias de metacercaria de austrodiplostomum compactum lutz 1928 platyhelminthes digenea parasito de olhos de peixes da bacia do rio parana
Revista Brasileira De Parasitologia Veterinaria, 2008Co-Authors: Fabio Hideki Yamada, Ricardo Massato Takemoto, Luis Henrique De Aquino Moreira, Tiago Lopes Ceschini, Gilberto Cezar PavanelliAbstract:Austrodiplostomum compactum (Platyhelminthes, Digenea) eye flukes of several species of fishes. The presence of this parasite, in extreme cases, can cause swelling of the eyelids, displacement of the retina, opacity of the crystalline lens and blindness or even death. The present study it registers new occurrences of this metacercariae infecting the eyes of four new hosts of fish, Serrasalmus maculatus collected in the Rosana reservoir in the Paranapanema river and Hypostomus regani, Schizodon borellii and Auchenipterus osteomystax collected in the the Upper Parana River floodplain.
-
Copépodes parasitos de fossas nasais de cinco espécies de peixes (Characiformes) da planície de inundação do alto rio Paraná, Paraná, Brasil - DOI: 10.4025/actascibiolsci.v29i4.887
Acta Scientiarum. Biological Sciences, 2008Co-Authors: Ana Carolina Figueiredo Lacerda, Ricardo Massato Takemoto, Maria De Los Angeles Perez Lizama, Gilberto Cezar PavanelliAbstract:The present work had the objective to study parasitic copepods in the nasal fossae of fish from the upper Parana river floodplain. Fish were captured in different locations of the floodplain in March, June and September, 2004. A total of 73 specimens (Characiformes) were collected, belonging to 4 distinct families and 5 species: Acestrorhynchus lacustris (Acestrorhynchidae), Schizodon borellii (Anostomidae), Prochilodus lineatus (Prochilodontidae), Serrasalmus marginatus and Serrasalmus maculatus (Serrasalmidae). Among 73 fishes examined, 53 were parasitized by nasal fossae copepods, varying from 1 to 146 parasites per host. Parasites found belonged to 3 known species: Gamidactylus jaraquensis Thatcher & Boeger, 1984; Gamispatulus schizodontis Thatcher & Boeger, 1984; and Rhinergasilus piranhus Boeger & Thatcher, 1988. There were differences in parasite corporal measurements and in the quantity of parasites per host in relation to copepod parasites from the Amazon region. The present study constitutes one of the few studies of identification of copepod parasites in the nasal fossae of fish from the Southern region of Brazil.
Daniel C. Carvalho - One of the best experts on this subject based on the ideXlab platform.
-
Invasion dynamics of the white piranha ( Serrasalmus brandtii ) in a Neotropical river basin
Biological Invasions, 2019Co-Authors: Daniel Fonseca Teixeira, Francisco Ricardo Andrade Neto, Laís Carvalho Gomes, Luciano B. Beheregaray, Daniel C. CarvalhoAbstract:Clarifying the intricate history of unrecorded fish invasions represents an important step in understanding the invasion process. Here, we elucidate the invasion of a Neotropical river basin in Southeastern Brazil by a very efficient predator, the white piranha (Serrasalmus brandtii). We used a temporal series of population dynamics data (2008–2016) and analyses of mitochondrial DNA sequences (COI, 16S, and control region) of specimens from the entire native (Sao Francisco River Basin, Southeastern Brazil) and invaded (Jequitinhonha River Basin, JRB) ranges. We detected low genetic diversity (h = 0.5835) and strong genetic structure in the invasive range (Fst = 0.9141), despite high genetic diversity (h = 0.8900) and low genetic structure (Fst from 0.0740 to 0.1348) in the native range. High genetic structure in the invaded range was associated with a hydroelectric dam that prevented the admixture of two independent introductory acts into the JRB (downstream and upstream of the Irape Dam). The rapid invasion capability of Serrasalmus brandtii, with few propagules, indicates that the species should be included in ecological risk assessments for restocking efforts of other commercially or ecologically important fish species and dam construction in Brazil. The combination of genetic and population dynamic datasets enabled the reconstruction of a top predator fish invasion in the Neotropics and shed light on ecological factors that influenced its invasion success.
Gilberto Cezar Pavanelli - One of the best experts on this subject based on the ideXlab platform.
-
novas ocorrencias de metacercaria de austrodiplostomum compactum lutz 1928 platyhelminthes digenea parasito de olhos de peixes da bacia do rio parana
Revista Brasileira De Parasitologia Veterinaria, 2008Co-Authors: Fabio Hideki Yamada, Ricardo Massato Takemoto, Luis Henrique De Aquino Moreira, Tiago Lopes Ceschini, Gilberto Cezar PavanelliAbstract:Austrodiplostomum compactum (Platyhelminthes, Digenea) eye flukes of several species of fishes. The presence of this parasite, in extreme cases, can cause swelling of the eyelids, displacement of the retina, opacity of the crystalline lens and blindness or even death. The present study it registers new occurrences of this metacercariae infecting the eyes of four new hosts of fish, Serrasalmus maculatus collected in the Rosana reservoir in the Paranapanema river and Hypostomus regani, Schizodon borellii and Auchenipterus osteomystax collected in the the Upper Parana River floodplain.
-
Copépodes parasitos de fossas nasais de cinco espécies de peixes (Characiformes) da planície de inundação do alto rio Paraná, Paraná, Brasil - DOI: 10.4025/actascibiolsci.v29i4.887
Acta Scientiarum. Biological Sciences, 2008Co-Authors: Ana Carolina Figueiredo Lacerda, Ricardo Massato Takemoto, Maria De Los Angeles Perez Lizama, Gilberto Cezar PavanelliAbstract:The present work had the objective to study parasitic copepods in the nasal fossae of fish from the upper Parana river floodplain. Fish were captured in different locations of the floodplain in March, June and September, 2004. A total of 73 specimens (Characiformes) were collected, belonging to 4 distinct families and 5 species: Acestrorhynchus lacustris (Acestrorhynchidae), Schizodon borellii (Anostomidae), Prochilodus lineatus (Prochilodontidae), Serrasalmus marginatus and Serrasalmus maculatus (Serrasalmidae). Among 73 fishes examined, 53 were parasitized by nasal fossae copepods, varying from 1 to 146 parasites per host. Parasites found belonged to 3 known species: Gamidactylus jaraquensis Thatcher & Boeger, 1984; Gamispatulus schizodontis Thatcher & Boeger, 1984; and Rhinergasilus piranhus Boeger & Thatcher, 1988. There were differences in parasite corporal measurements and in the quantity of parasites per host in relation to copepod parasites from the Amazon region. The present study constitutes one of the few studies of identification of copepod parasites in the nasal fossae of fish from the Southern region of Brazil.
-
Parasitic copepo opepodsthe nasal fossae of five fish species in the nasal fossae of five fish species in the nasal fossae of five fish species in the nasal fossae of five fish species (Characiformes) from the upper Paraná (Characiformes) from the up
2007Co-Authors: Ana Carolina, Figueiredo Lacerda, Ricardo Massato Takemoto, Perez Lizama, Gilberto Cezar PavanelliAbstract:The present work had the objective to study parasitic copepods in the nasal fossae of fish from the upper Parana river floodplain. Fish were captured in different locations of the floodplain in March, June and September, 2004. A total of 73 specimens (Characiformes) were collected, belonging to 4 distinct families and 5 species: Acestrorhynchus lacustris (Acestrorhynchidae), Schizodon borellii (Anostomidae), Prochilodus lineatus (Prochilodontidae), Serrasalmus marginatus and Serrasalmus maculatus (Serrasalmidae). Among 73 fishes examined, 53 were parasitized by nasal fossae copepods, varying from 1 to 146 parasites per host. Parasites found belonged to 3 known species: Gamidactylus jaraquensis Thatcher & Boeger, 1984; Gamispatulus schizodontis Thatcher & Boeger, 1984; and Rhinergasilus piranhus Boeger & Thatcher, 1988. There were differences in parasite corporal measurements and in the quantity of parasites per host in relation to copepod parasites from the Amazon region. The present study constitutes one of the few studies of identification of copepod parasites in the nasal fossae of fish from the Southern region of Brazil. RESUMO. Copepodes parasitos de fossas nasais de cinco especies de peixes (Characiformes) da planicie de inundacao do alto rio Parana, Parana, Brasil. O presente trabalho teve como objetivo o estudo de copepodes parasitos de fossas nasais de peixes da planicie de inundacao do alto Rio Parana. As coletas foram realizadas em diversos pontos da planicie nos meses de marco, junho e setembro de 2004. Foram coletados 73 exemplares de peixes da ordem Characiformes, de quatro familias distintas, pertencentes a cinco especies: Acestrorhynchus lacustris , Prochilodus lineatus , Schizodon borellii, Serrasalmus maculatus e Serrasalmus marginatus . Dentre os 73 peixes examinados, 53 encontravam-se parasitados por copepodes de fossas nasais, variando de 1 a 146 parasitos por peixe. Os parasitos encontrados pertenciam a tres especies conhecidas: Gamidactylus jaraquensis Thatcher & Boeger, 1984; Gamispatulus schizodontis Thatcher & Boeger, 1984 e Rhinergasilus piranhus Boeger & Thatcher, 1988. Diferencas foram observadas nas medidas corporais dos parasitos e na quantidade de especies de parasitos por especie de peixe em relacao aos copepodes encontrados em estudos anteriores na regiao amazonica. O presente estudo constitui um dos poucos trabalhos de identificacao de copepodes parasitos de fossas nasais de peixes da regiao Sul do Brazil.
-
(Characiformes) from the upper Paraná (Characiformes) from the upper Paraná (Characiformes) from the upper Paraná (Characiformes) from the upper Paraná r iverfloodplain, Paraná, floodplain, Paraná,
2007Co-Authors: Ana Carolina, Figueiredo Lacerda, Ricardo Massato Takemoto, Perez Lizama, Gilberto Cezar PavanelliAbstract:The present work had the objective to study parasitic copepods in the nasal fossae of fish from the upper Parana river floodplain. Fish were captured in different locations of the floodplain in March, June and September, 2004. A total of 73 specimens (Characiformes) were collected, belonging to 4 distinct families and 5 species: Acestrorhynchus lacustris (Acestrorhynchidae), Schizodon borellii (Anostomidae), Prochilodus lineatus (Prochilodontidae), Serrasalmus marginatus and Serrasalmus maculatus (Serrasalmidae). Among 73 fishes examined, 53 were parasitized by nasal fossae copepods, varying from 1 to 146 parasites per host. Parasites found belonged to 3 known species: Gamidactylus jaraquensis Thatcher & Boeger, 1984; Gamispatulus schizodontis Thatcher & Boeger, 1984; and Rhinergasilus piranhus Boeger & Thatcher, 1988. There were differences in parasite corporal measurements and in the quantity of parasites per host in relation to copepod parasites from the Amazon region. The present study constitutes one of the few studies of identification of copepod parasites in the nasal fossae of fish from the Southern region of Brazil.
-
neotropical monogenoidea 39 a new species of kritskyia dactylogyridae ancyrocephalinae from the ureters and urinary bladder of Serrasalmus marginatus and s spilopleura characiformes serrasalmidae from southern brazil with an
Zoosystema, 2001Co-Authors: Walter A. Boeger, Lucia K Tanaka, Gilberto Cezar PavanelliAbstract:Kritskyia annakohnae n. sp. (Dactylogyridae, Ancyrocephalinae) est decrit a partir d'individus parasites des ureteres et de la vessie urinaire des piranhas Serrasalmus marginatus Valenciennes, 1836 et S. spilopleura Kner, 1858 (Characiformes, Serrasalmidae) du Rio Baia, Parana, Bresil. La nouvelle espece est caracterisee par une protuberance sur le cote gauche du tronc, ainsi que par une piece accessoire comprenant deux sous-unites paralleles, fusionnees aux deux extremites, proximale et distale. Une nouvelle diagnose du Kritskyia Kohn, 1990 est proposee. En depit d'une proposition anterieure, Kritskyia ne s'apparente pas a d'autres Dactylogyridae qui n'ont ni ancres ni barres transversales haptorales. Les connaissances actuelles sur la morphologie et la phylogenie indiquent que la perte de ces sclerites a eu lieu plusieurs fois et independamment dans la famille.
Luiz Carlos Gomes - One of the best experts on this subject based on the ideXlab platform.
-
Adjustments in population and reproductive dynamics of native and non-native congeneric species during 26 years after invasion
Neotropical Ichthyology, 2021Co-Authors: Amanda Cantarute Rodrigues, Matheus T. Baumgartner, Natália Carneiro Lacerda Dos Santos, Luiz Carlos GomesAbstract:ABSTRACT We aimed to improve the understanding of the establishment of Serrasalmus marginatus (non-native), which was followed by a decrease in the abundance of Serrasalmus maculatus (native) in the upper Paraná River floodplain. We estimated age, mortality rate, length and age at first maturity and variations in gonad development in three time-periods along a 26-year truncated time scale for both species. Population and reproduction parameters of both species showed substantial fluctuations among periods. Most age classes were sampled in all time-periods, but with considerable difference in abundance, with predominance of older individuals in the second time-period and younger individuals in the third time-period for both species. The mortality rates decreased for both species in the second time-period, but increased for the native in the third time-period. Length and age at first maturity decreased in the second time-period for both species, increasing the number of mature individuals on their populations. In the third time-period, the number of immature individuals increased for both species. We suggest that species experienced stressful conditions during cooccurrence and this have resulted in physiological responses in both species, reflecting in population and reproductive adjustments that may have relaxed competitive interactions between them, optimizing survival, reproductive effort and coexistence.
-
Coexistence between native and nonnative species: the invasion process and adjustments in distribution through time for congeneric piranhas in a Neotropical floodplain
Hydrobiologia, 2018Co-Authors: Amanda Cantarute Rodrigues, Herick Soares De Santana, Matheus T. Baumgartner, Luiz Carlos GomesAbstract:Our goal was to report the progress of Serrasalmus marginatus invasion process in the upper Parana River floodplain by exploring its mechanisms and coexistence with its native congeneric Serrasalmus maculatus. We described their temporal abundance variations; nonnative species’ predominance in specific habitats; recruitment effectiveness for both species and its spatial variations; spatial organization pattern of native and nonnative species; and how their abundance is related to their co-occurrence. Abundance data encompassed 26 years after the invasion, while the proportion analyses between the species occurred on a monthly basis and in different environments, and the spatial organization pattern was assessed using C-score index. Results showed that the population of nonnative species had a fast increase along the early years followed by a decrease in the population of the native species. Recently, their proportion seems to be stabilizing, apparently resulting from a differentiation on the use of resources. The species are allowed by the spatial organization pattern to coexist in the floodplain, despite their variable co-occurrence in different environments. It is possible to state the persistence of native species in the floodplain at lower abundances in relation to the nonnative species as well as when occupying different habitats.
-
Larval fish assemblage in the Baía River (Mato Grosso do Sul State, Brazil): temporal and spatial patterns
Environmental Biology of Fishes, 2005Co-Authors: Andréa Bialetzki, Keshiyu Nakatani, Paulo Vanderlei Sanches, Gilmar Baumgartner, Luiz Carlos GomesAbstract:We sampled the Baia River (Mato Grosso do Sul State, Brazil) monthly, to survey taxonomic composition and temporal and spatial distribution of fish larvae. The ichthyoplankton was mainly composed by larvae of small and medium sized sedentary species and it was numerically dominated by six taxa: Plagioscion squamosissimus, Hypophthalmus edentatus, Hoplias aff. malabaricus, Bryconamericus stramineus, Serrasalmus spp. and Catathyridium jenynsii. These taxa present distinct temporal and spatial occurrence patterns: H. edentatus, B. stramineus and C. jenynsii are abundant between September and March in lentic areas; H. aff. malabaricus and Serrasalmus spp. were caught between October and February in lotic areas; whereas P. squamosissimus occurs in all sampled areas, with peak of capture in January. Hypophthalmus edentatus, H. aff. malabaricus, Serrasalmus spp. and B. stramineus were the taxa that most contributed to structure the assemblages temporally and spatially, and their abundances were influenced by the interaction of several environmental variables.
-
relacao estoque recrutamento para as piranhas Serrasalmus marginatus valenciennes 1847 e s maculatus kner 1860 no rio baia alto rio parana doi 10 4025 actascibiolsci v26i3 1544
Acta Scientiarum. Biological Sciences, 2004Co-Authors: Patricia Catelan Alexandre, Luiz Carlos Gomes, Elaine Antoniassi Luiz, Pitagoras Augusto Piana, Angelo Antonio AgostinhoAbstract:Stock and recruitment relationship for Serrasalmus marginatus (Valenciennes, 1847) and S. maculatus (Kner, 1860) piranhas in Baia River, Upper Parana River. The most important and, usually, the most difficult problem in fisheries sciences assessment is the relationship between stock and recruitment. The term 'recruitment' is referred in this study as the abundance of the earliest age at which a cohort can effectively be estimated. The process of recruitment is complex, and determined by density-dependent and density-independent factors. Usually, stock-recruitment is the empirical relationship between reproductive stock and the number of recruits produced. There are several suggestions to express the stock-recruitment relationship, and an example of such attempts is the models of Beverton and Holt, Ricker and Shepherd. These models were fitted by non-linear procedure to Serrasalmus marginatus and S. maculatus populations from the Baia River. The aim of the study was to determine the best model for stock- recruitment relationship and the main mechanism related to it for both species. Competition appeared to be the limiting factor for recruitment. Shepherd (S. marginatus)
Carlos Sergio Agostinho - One of the best experts on this subject based on the ideXlab platform.
-
molecular characterization and genetic relationships of seven piranha species of the genera Serrasalmus and pygocentrus characiformes serrasalmidae from parana paraguay sao francisco and tocantins river basins in brazil
Brazilian Journal of Biology, 2019Co-Authors: Thais Souto Bignotto, Carlos Sergio Agostinho, V N Gomes, T C Maniglia, Talge Aiex Boni, Sonia Maria Alves Pinto Prioli, Alberto Jose PrioliAbstract:: Genetic and phylogenetic relationships among seven piranha species of the genera Serrasalmus and Pygocentrus from the Parana-Paraguay, Sao Francisco and Tocantins River basins were evaluated in the present study by partial sequences of two mitochondrial genes, Cytochrome b and Cytochrome c Oxidase I. Phylogenetic analysis of Maximum-Likelihood and Bayesian inference were performed. Results indicated, in general, greater genetic similarity between the two species of Pygocentrus (P. nattereri and P. piraya), between Serrasalmus rhombeus and S. marginatus and between S. maculatus, S. brandtii and S. eigenmanni. Pygocentrus nattereri, S. rhombeus and S. maculatus showed high intraspecific genetic variability. These species have each one, at least two different mitochondrial lineages that, currently, occur in sympatry (S. rhombeus) or in allopatry (P. nattereri and S. maculatus). Species delimitation analysis and the high values of genetic distances observed between populations of S. rhombeus and of S. maculatus indicated that each species may corresponds to a complex of cryptic species. The non-monophyletic condition of S. rhombeus and S. maculatus reinforces the hypothesis. The geographic distribution and the genetic differentiation pattern observed for the piranha species analyzed herein are discussed regarding the geological and hydrological events that occurred in the hydrographic basins.
-
Fish ladders: safe fish passage or hotspot for predation?
Neotropical Ichthyology, 2012Co-Authors: Angelo Antonio Agostinho, Carlos Sergio Agostinho, Fernando Mayer Pelicice, Elineide Eugênio MarquesAbstract:Fish ladders are a strategy for conserving biodiversity, as they can provide connectivity between fragmented habitats and reduce predation on shoals that accumulate immediately below dams. Although the impact of predation downstream of reservoirs has been investigated, especially in juvenile salmonids during their downstream movements, nothing is known about predation on Neotropical fish in the attraction and containment areas commonly found in translocation facilities. This study analysed predation in a fish passage system at the Lajeado Dam on the Tocantins River in Brazil. The abundance, distribution, and the permanence (time spent) of large predatory fish along the ladder, the injuries imposed by piranhas during passage and the presence of other vertebrate predators were investigated. From December 2002 to October 2003, sampling was conducted in four regions (downstream, along the ladder, in the forebay, and upstream of the reservoir) using gillnets, cast nets and counts or visual observations. The captured fish were tagged with thread and beads, and any mutilations were registered. Fish, birds and dolphins were the main predator groups observed, with a predominance of the first two groups. The entrance to the ladder, in the downstream region, was the area with the highest number of large predators and was the only region with relevant non-fish vertebrates. The main predatory fish species were Rhaphiodon vulpinus, Hydrolycus armatus, and Serrasalmus rhombeus. Tagged individuals were detected predating along the ladder for up to 90 days. Mutilations caused by Serrasalmus attacks were noted in 36% of species and 4% of individuals at the top of the ladder. Our results suggested that the high density of fish in the restricted ladder environment, which is associated with injuries suffered along the ladder course and the presence of multiple predator groups with different predation strategies, transformed the fish corridor into a hotspot for predation.
-
invasao da piranha Serrasalmus marginatus valenciennes 1847 no alto rio parana brasil osteichthyes serrasalmidae
Acta Scientiarum. Biological Sciences, 2008Co-Authors: Carlos Sergio Agostinho, Horácio Ferreira JúlioAbstract:The building of Itaipu Dam, 150 km downstream from Sete Quedas Falls, resulted in the natural geographical barrier drowning, with subsequent mixing of the fish faunas. Serrasalmus marginatus (Osteichthyes, Serrasalmidae), a species that had been restricted to the river segment downstream from Sete Quedas, invaded the Upper Parana River. The catching of Serrasalmus spilopleura , a resident species, decreased drastically after the invasion, contrary to S. marginatus , which increased in abundance. In the Piquiri River, where the latter species does not occur, the abundance of S. spilopleura remained high, due to the presence of Nha Barbara and Apertado Falls.
-
Reproductive aspects of piranhas Serrasalmus spilopleura and Serrasalmus marginatus into the upper Paraná River, Brazil.
Brazilian journal of biology = Revista brasleira de biologia, 2003Co-Authors: Carlos Sergio AgostinhoAbstract:Construction of the Itaipu Dam, 150 km downstream from Sete Quedas Falls, resulted in the drowning of that natural geographic barrier, with consequent invasion of Serrasalmus marginatus in the upper stream. This event was followed by the reduction in the abundance of the native species, S. spilopleura. Analyzes of reproductive activity these species revealed that in lotic waters S. marginatus had a very intense reproductive activity while activity of S. spilopleura was nil. This, probably made it possible for the invading species to occupy new environments into the Upper Parana River, using the river as an entry port. In the 1987-1988 period there was a marked decline in reproductive activity of S. spilopleura reflecting the negative effects of its interaction with the invading species, S. marginatus. The assertiveness of S. marginatus in caring for its offspring and aggressiveness in establishing its feeding territory may be the determining factor for its competitive superiority over S. spilopleura, and consequently its success in colonizing the Upper Parana River. In addition to the negative interference of S. marginatus, a possible recruitment failure of S. spilopleura could have benefited the colonization of the floodplain by the invader species.
-
Observation of an invasion of the piranha Observation of an invasion of the piranha Observation of an invasion of the piranha Observation of an invasion of the piranha Serrasalmus marginatus Serrasalmus marginatus
2002Co-Authors: Carlos Sergio Agostinho, Horácio Ferreira JúlioAbstract:The building of Itaipu Dam, 150 km downstream from Sete Quedas Falls, resulted in the natural geographical barrier drowning, with subsequent mixing of the fish faunas. Serrasalmus marginatus (Osteichthyes, Serrasalmidae), a species that had been restricted to the river segment downstream from Sete Quedas, invaded the Upper Parana River. The catching of Serrasalmus spilopleura , a resident species, decreased drastically after the invasion, contrary to S. marginatus , which increased in abundance. In the Piquiri River, where the latter species does not occur, the abundance of S. spilopleura remained high, due to the presence of Nha Barbara and Apertado Falls.
