The Canal da Piracema is the longest (nearly 10 km) fish pass system in world. construction of this was somehow controversial, because it connected two distinct ichthyofaunistic provinces. This study evaluated ichthyofauna present and abundance distribution long-distance migratory species along (evaluated possible selectivity). shown to be difficult sample its environmental heterogeneity: artificial ponds, ladders nature-like pass. To solve problem, we used several fishing gears, adequate...

Migratory behaviour of selected fish species is described in the Paraná River, Brazil–Argentina–Paraguay, to search for patterns relevant tropical regulated river systems. In a 10 year mark–recapture study, spanning 1425 km section river, 32 867 fishes composed 18 were released and 1083 recaptured. The recaptured at liberty an average 166 days (maximum 1548 days) travelled 35 (range 0–625 km). Cluster analysis applied variables descriptive movement identified four general patterns. 1...

Abstract Regulation of rivers by dams transforms previously lotic reaches above the dam into lentic ones and limits or prevents longitudinal connectivity, which impairs access to suitable habitats for reproduction many migratory fish species. Frequently, unregulated tributaries can provide important habitat heterogeneity a regulated river may mitigate influence impoundments on mainstem river. We evaluated importance spawning species over three seasons, comparing several abiotic conditions...

The purpose of this study was to evaluate the role abiotic factors on fish larvae occurrence. Samplings were carried out monthly at 12 stations (grouped in four areas) Amambaí, Ivaí and Paraná rivers Itaipu Reservoir (upper River basin), from October 1994 January 1995 (spawning season). Simultaneously, we obtained water temperature, pH, electrical conductivity, dissolved oxygen, level, velocity, rainfall. Principal Component Analyses (PCA) Detrended Correspondence (DCA) applied summarize...

Abstract Conservation of fish assemblages in severely impounded rivers has often focused on providing longitudinal and lateral connectivity along the main stem. Less attention been given to tributaries, some which remain unimpounded. This study shows that biodiversity ichthyoplankton tributaries largest reservoir Paraná River, Brazil, is similar few remaining unimpounded stretches River. Annual seasonal variability discharge within among attracts supports a diverse mix species each spawning...

Utilization of the fish ladder installed at Engenheiro Sergio Motta Dam (also known as Porto Primavera) on Paraná River, Southern Brazil, by long-distance migrating potamodromous species (sampling Protocol I), and ascending descending movements (Protocol II) were evaluated. Three pools along (designated lower, middle, upper) sampled monthly between December, 2004 March, 2005 to determine abundance in ladder. The also analyzed same period. In samples for both protocols, 37 representing 17...

Abstract The conservation of migratory fish species worldwide has been threatened by the loss longitudinal connectivity caused dams intercepting large rivers. One environmental management strategy for reestablishing is providing passage through ladders. However, ladders in Neotropical rivers have described as ascending one‐way routes. We analysed movements Prochilodus lineatus a ladder at dam—Porto Primavera—in heavily impounded Upper Paraná River, Brazil, to determine whether connected...

South American rivers have become intensely affected by the construction of hydroelectric dams that block river’s connectivity for migratory fish species. In order to mitigate problems caused and reestablish connections between habitats, fishways are implemented. Fishways structures aid in overcoming obstacles help preserve migratory, reproductive, feeding routes. This study performed an inventory all hydropower plants—present future—in Upper Paraná River, with objective identifying unknown...

Abstract The Piracema Canal is a complex 10‐km fish pass system that climbs 120 m to connect the Paraná River Itaipu Reservoir along Brazil–Paraguay border. canal was constructed allow migratory fishes reach suitable habitats for reproduction and feeding in tributaries upstream from reservoir. attracted 17 of 19 long‐distance species have been recorded Basin Paraguay–Paraná Basin. However, incidence decreased downstream upstream, with pattern decrease depending on species. Overall, 0.5%...

This paper presents results of a fishway evaluation performed at the Engenheiro Sérgio Motta Hydroelectric Power Plant (known as Porto Primavera) - CESP, Paraná River, Brazil. The was designed to quantify entry and passage proportions 4 long-distance migratory fish species: Brycon orbignyanus (piracanjuba), Piaractus mesopotamicus (pacu), Prochilodus lineatus (curimba), Rhinelepis aspera (cascudo-preto). Proportions finding entering differed between species, ranged from 7.4 % (Prochilodus...

This study investigated the external body morphology (based on morphometric data) and swimming efficiency in fish passages ascent time a ladder) of two Neotropical long-distance migratory species. The were collected ladder Porto Primavera Hydroelectric Power Plant (known as Engenheiro Sergio Motta), upper Paraná River, Brazil. species differ several ratios related to performance. Prochilodus lineatus exhibited higher muscle ratio caudal fin length ratio. However, Leporinus elongatus showed...

The management of water resources is a complex issue, and the conservation fish fishery growing challenge given increase in number hydroelectric projects Brazilian river basins. This study describes fragmentation Tocantins–Araguaia River Basin resulting from installation plants operation planned by electricity sector until 2050, as well its relationship with fauna, especially long-distance migratory species. were analyzed using data obtained National Electric Energy Agency. A literature...

Larvae feeding selectivity of Iheringichthys labrosus , Hypophthalmus edentatus and Plagioscion squamosissimus was assessed, examining the role mouth gape in prey selection. Fish larvae were sampled Itaipu Reservoir (Brazil–Paraguay). H. larvae, with small similar sizes, exhibited slightly different diets; I. preferred cladocerans ( Bosmina hagmanni huauriensis Bosminopsis deitersi ) rotifer Brachionus calyciflorus . however, primarily ingested B. Ceriodaphnia cornuta Daphnia gessneri...

Gymnogeophagus setequedas is a rare and rheophilic species of tribe Geophagini, considered endangered in Brazilian red lists. Its previously known geographical distribution range was the Paraná River basin, Paraguay, tributary Itaipu Reservoir Brazil. Since its description no specimens have been collected original area. However, recent records G. lower Iguaçu River, region highly endemic for ichthyofauna, extended may represent one last remnants species. The aim this study to estimate...

Improperly installed or poorly maintained culverts can pose a serious threat to fish by disrupting their habitat and endangering spawning success. Road that are not designed for passage frequently become obstacles. This be especially problematic migratory species, but lead fragmentation of resident populations as well. study evaluated 40 29 sites within 25-km radius from Toledo city, Paraná State, southern Brazil, with respect likely effects on movement the local ichthyofauna. We collected...

We evaluated the effectiveness of fish ladder at Porto Primavera Dam in severely regulated Upper Paraná River, for two Neotropical migratory species. Overall, 564 (448Megaleporinus obtusidens and 116M. piavussu) were PIT-tagged, released upstream downstream areas (on left right banks), monitored continuously 4 years. The performed two-way movements through ladder, ascending from tailrace descending forebay. registered entry into fishway 46M. (10.3%) individuals only three M. piavussu (2.6%)...

ABSTRACT This study described the initial development of Pseudoplatystoma reticulatum, as well changes in growth patterns. Morphometric and meristic variables were analyzed during embryonic, larval juvenile periods, even allometric coefficients for larvae juveniles. Eggs showed an average diameter 1.79 mm broad perivitelline space (23.41%). The total length (TL) ranged from 3.05 to 25.72 mm, number myomeres 45 50 (preanal = 13-16 postanal 30-35). Initial pigmentation is poor, concentrated at...

A mark-recapture study was conducted in 1997–2005 to investigate movements of stocked pacu, Piaractus mesopotamicus, the Paraná River Basin Brazil, Paraguay, and Argentina. Fish raised cages within Itaipu Reservoir ponds were tagged externally (n = 2976) released (53.2%) bays its major tributaries (46.8%). In total, 367 fish (12.3%) recaptured. all, 91% pacu moved away from release site; upstream more extensive than downstream movements. Pacu traveled a maximum 422 km (average 41.3 km) at...

This study evaluated the environmental conditions of two watersheds selected on basis similarities in land use. The were analyzed using geoprocessing methods and situ evaluations by applying rapid assessment protocol (RAP). Geospatial image processing was used to analyze use, slope, soil classification, rainfall, while RAP evaluate connectivity size riparian corridors. results revealed varied uses with landscape matrix both watersheds, composed agriculture, pasture, urban centers. Urban...

The aim of this study was to characterize the early development Hoplias aff. malabaricus. sampling conducted during period from November 1991 through February 1995, at 42 stations distributed in different environments upper Paraná river floodplain, Brazil. specimens were taken limnetic and littoral regions. Specimens separated according their larval (preflexion, flexion postflexion stages) juvenile periods. Morphometric meristic variables analyzed 269 larvae 74 juveniles (standard length...

ABSTRACT Resource partitioning allows for interspecific coexistence and is frequently reported similar species. Here, we predicted the existence of resource among species Astyanax that co-occur in Low Iguaçu River tributaries Brazil. A total 848 stomachs five were analyzed. Algae, terrestrial plant fruit/seed most consumed resources. bifasciatus A. dissimilis had predominantly herbivorous diets, gymnodontus lacustris omnivorous, minor was mainly algivorous. Permutational analysis variance...

O objetivo deste estudo foi descrever o desenvolvimento embrionário, larval e juvenil da jurupoca, Hemisorubim platyrhynchos (Valenciennes, 1840), bem como as mudanças nos padrões de crescimento alométrico durante a ontogenia inicial espécie. Um total 90 ovos, 210 larvas 24 juvenis provenientes reprodução induzida foram analisados quanto variáveis morfométricas merísticas, além do coeficiente em relação à cabeça, tronco cauda período inicial. Os ovos apresentaram diâmetro médio 1,74 mm,...