نتایج جستجو برای: fish assemblage

تعداد نتایج: 111884  

Journal: :Brazilian journal of biology = Revista brasleira de biologia 2009
W S Smith M Petrere W Barrella

A fish assemblage study was accomplished in different habitats of the Sorocaba River Basin. Fish were caught with gillnets, were weighed (weight total - g) and measured (standard length - mm). Several abiotic variables of selected sampling sites were measured in order to characterise their habitats in order to attempt establishing correlations with fish community traits. Fish numbers per specie...

2013
Yohei Nakamura David A. Feary Masaru Kanda Kosaku Yamaoka

Climate change is resulting in rapid poleward shifts in the geographical distribution of tropical and subtropical fish species. We can expect that such range shifts are likely to be limited by species-specific resource requirements, with temperate rocky reefs potentially lacking a range of settlement substrates or specific dietary components important in structuring the settlement and success o...

2016
Allison H. Roy Mary C. Freeman Byron J. Freeman Seth J. Wenger William E. Ensign Judith L. Meyer A. H. ROY M. C. FREEMAN J. L. MEYER

Stream biota in urban and suburban settings are thought to be impaired by altered hydrology; however, it is unknown what aspects of the hydrograph alter fish assemblage structure and which fishes are most vulnerable to hydrologic alterations in small streams. We quantified hydrologic variables and fish assemblages in 30 small streams and their subcatchments (area 8–20 km2) in the Etowah River C...

2004
Phillip S. Levin Elizabeth E. Holmes Kevin Piner

The US Pacific Coast has been largely free of fishery collapses that have occurred elsewhere, but the situation appears to be changing. Here, we show results from the first systematic study of demersal fishes along the US Pacific Coast. Using data from a quarter-century long, fishery-independent, coast-wide trawl survey, we document fundamental shifts in the demersal fish assemblage along the U...

2014
Sergio Santorelli William Magnusson Efrem Ferreira Erica Caramaschi Jansen Zuanon Sidnéia Amadio

Hypotheses about phylogenetic relationships among species allow inferences about the mechanisms that affect species coexistence. Nevertheless, most studies assume that phylogenetic patterns identified are stable over time. We used data on monthly samples of fish from a single lake over 10 years to show that the structure in phylogenetic assemblages varies over time and conclusions depend heavil...

ژورنال: علمی شیلات ایران 2014
ربانی ها, مهناز, عطاران فریمانی, گیلان, موسوی گل سفید, سید علی, نصیری, حمیدرضا,

The survey of fish larvae assemblage variation was done in 2013 seasonally at the coastal areas of Southeastern side of Chabahar Bay. Sampling was done in 3 stations at day and night periods by a Bongo-Net with 300μ of mesh size. 29 families were identified. Clupeidae, Gobiidae and Blenniidae were dominant with more than 50% relative abundance. The PCA result was shown there were two separated ...

Journal: :Ecology 1987
S R Carpenter J F Kitchell J R Hodgson P A Cochran J J Elser M M Elser D M Lodge D Kretchmer X He C N von Ende

We performed whole-lake manipulations of fish populations to test the hypothesis that higher trophic levels regulate zooplankton and phytoplankton community structure, biomass, and primary productivity. The study involved three lakes and spanned 2 yr. Results demonstrated hierarchical control of primary production by abiotic factors and a trophic cascade involving fish predation. In Paul Lake, ...

2005
C. A. Layman K. O. Winemiller

Traits used to group species and generalize predator–prey interactions can aid in constructing models to assess human impacts on food webs, especially in complex, species-rich systems. Commercial netting has reduced populations of large-bodied piscivores in some lagoons of a Venezuelan floodplain river, and cascading effects result in distinct prey fish communities in netted and unnetted lagoon...

2013
Peter C. Sakaris

Hydrologic alterations resulting from dam construction and other human activities have negatively impacted the biodiversity and ecological integrity of rivers worldwide (Dudgeon 2000, Pringle et al. 2000). These alterations have included habitat fragmentation, conversion of lotic to lentic habitat, variable flow and thermal regimes, degraded water quality, altered sediment transport processes, ...

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