27 research outputs found
Fish, lower Ivinhema River basin streams, state of Mato Grosso do Sul, Brazil.
The Ivinhema River basin is one of the main tributaries of the western portion of ParanĂĄ River. However,few data are available on the fish communities of its streams. Monthly samples were made in seven streams of the lowerportion of the basin, in the state of Mato Grosso do Sul, using a rectangular sieve 1.2 x 0.8 m, with 2 mm mesh size.Forty-six fish species were found in these streams. The richness estimated according to the bootstrap procedure was 50species. At least two of the captured species were not previously recorded for the upper ParanĂĄ basin, indicating theneed of new sampling effort in this region
Influence of the riparian zone phytophysiognomies on the longitudinal distribution of fishes: evidence from a Brazilian savanna stream
Structure and integrity of fish assemblages in streams associated to conservation units in Central Brazil
The influence of environmental variables on the functional structure of headwater stream fish assemblages: a study of two tropical basins in Central Brazil
Spatial pattern of a fish assemblage in a seasonal tropical wetland: effects of habitat, herbaceous plant biomass, water depth, and distance from species sources
Patterns in fish species composition and assemblage structure in the upper Salado River lakes, Pampa Plain, Argentina
Spatial and temporal distribution of fish larvae in marginal lagoons of Pantanal, Mato Grosso State, Brazil
Estudo comparado da taxocenose de peixes em dois ambientes aquĂĄticos do Parque Estadual de ItapuĂŁ, sul do Brasil
Trophic ecology of Hemigrammus marginatus Ellis, 1911 (Characiformes, Characidae) in a conserved tropical stream
Reproductive ecology of Otocinclus vittatus (Regan, 1904) in the Pantanal floodplain, upper Paraguay River basin
Abstract We studied the reproductive biology of Otocinclus vittatus in the southern Pantanal, Brazil. A total of 1066 fishes were analyzed (490 males, 488 females and 88 individuals of undetermined sex), sampled with a rectangular sieve and a seine net from February/2009 to January/2011. Variations in the sex ratio, seasonality in reproduction, fecundity, and size at first maturity were estimated. No variations were detected in the total sex ratio for the study period as a whole; although ratio has varied over time. The gonadosomatic index varied according to the river level, but not according to water temperature and rainfall. The mean fecundity was estimated at 84.1 oocytes, with a positive correlation with standard length. The size at first maturity (L50) estimated was 18.7 mm for females and 20.1 mm for males