نتایج جستجو برای: caspian marine shad

تعداد نتایج: 96906  

2017
Omid Beyraghdar Kashkooli Joachim Gröger Ismael Núñez-Riboni

The worldwide occurrence of complex climate-induced ecological shifts in marine systems is one of the major challenges in sustainable bio-resources management. The occurrence of ecological environment-driven shifts was studied in the Southern Caspian Sea using the "shiftogram" method on available fisheries-related (i.e. commercially important bentho-pelagic fish stocks) ecological and climatic ...

2013
Mojtaba Mohseni Hamed Norouzi Javad Hamedi Aboulghasem Roohi

Actinomycetes are interesting as a main producer of secondary metabolites and industrial antibiotics from marine environments. A total of 44 strains of actinomycetes were isolated from Caspian Sea sediments at a depth of 5-10 m. Preliminary screening was done using cross-streak method against 2 gram-positive and 4 gram-negative pathogen bacteria. The most potent strains MN2, MN3, MN38, MN39, MN...

2008
JOEL C. HOFFMAN DEBORAH A. BRONK JOHN E. OLNEY

Our objective was to quantify the contribution of autochthonous, locally-produced phytoplankton, and allochthonous, terrestrial-derived organic matter (OM) to the production of young-of-year (YOY) American shad (Alosa sapidissima) using stable isotopes. We measured the carbon and nitrogen stable isotope composition of YOY American shad in the tidal fresh water of the Mattaponi River, a tributar...

2003
JOHN F. WALTER JOHN E. OLNEY

—Throughout its native range, American shad Alosa sapidissima is thought to cease feeding during anadromous migration. We examined the feeding habits of American shad during spawning migration by documenting changes in diet composition and feeding that occur in mature fish in the York River, Virginia. American shad were collected prior to and after spawning at various locations on a gradient fr...

2010
J. C. Smoot

The food source of sediment-ingesting animals is a subject of controversy, centering on the notion that the microbial biomass in sediments is insufficient to support caloric need. Gizzard shad Dorosoma cepedianum are omnivorous, sediment-ingesting fish that frequently impact the trophic structure of temperate lake and reservoir food webs. Prior gut content analyses of this fish have typically d...

2013
Paul .F. Mickle Jacob F. Schaefer Donald A. Yee Susan B. Adams

Understanding food-web ecology is valuable to conservation by linking interactions of multiple species together and illustrating the functionality of trophic exchange. Alosa alabamae (Alabama Shad), an anadromous species, reproduces in northern Gulf of Mexico drainages from February through May, and for this study, the Pascagoula and Apalachicola rivers were chosen to sample juvenile Alabama Sh...

2016
Isabel Casties Hanno Seebens Elizabeta Briski

Recently, several studies indicated that species from the Ponto-Caspian region may be evolutionarily predisposed to become nonindigenous species (NIS); however, origin of NIS established in different regions has rarely been compared to confirm these statements. More importantly, if species from certain area/s are proven to be better colonizers, management strategies to control transport vectors...

Journal: :Ecological applications : a publication of the Ecological Society of America 2009
Alberto Pilati Michael J Vanni María J González Alicia K Gaulke

Agricultural activities increase exports of nutrients and sediments to lakes, with multiple potential impacts on recipient ecosystems. Nutrient inputs enhance phytoplankton and upper trophic levels, and sediment inputs can shade phytoplankton, interfere with feeding of consumers, and degrade benthic habitats. Allochthonous sediments are also a potential food source for detritivores, as is sedim...

2017
JERRY H. HUBSCHMAN

Of 13 species of fish recorded as hosts for the acanthocephalan, Tanaorhamphus longirostris (Van Cleave 1913), only two regularly contain mature worms. These are the gizzard shad (Dorosoma cepedianum (Lesueur)) and the threadfin shad (D. petenense (Giinther)). To date, only one species of intermediate host, the calanoid copepod, Diaptomus pallidus Herrick, has been reported. In Caesar Creek Lak...

2004
ALEX HARO

Ahstn1~~-Pnssngc and trnnsit time of ndult upstream-migrant Amcricnn shnd Alosu sapidissima ~ n d blucback hcrring A. ucstivalls wcrc investigated in standard Dcnil and Alnska stecppass fishways with vnrinhlc slopc and hcndpond undcr scmicontrollcd condition^. Percent of Amcricnn hhad passcd per unit time (percent pnssnge) incrcnsed with temperature, while time required to lrom the lishway entr...

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