نتایج جستجو برای: fish scale

تعداد نتایج: 676245  

2015
ROBERT BRACKLEY COLIN BEAN

The potential for external damage to Atlantic salmon (Salmo salar L.) smolts from passage through an Archimedean screw turbine was tested with controlled field trials at two turbine speeds. Change in external condition of smolts was measured by grading photographs of individual fish for scale-loss before and after the tests. Results were compared between turbine-passed and control smolts. There...

M Khoramgah M.K Khalesi N Mirzakhani S Asgari s eskandari,

The Caspian Kutum, Rutilus Kutum (Kamensky 1901) specimens were sampled by purse seine in the northern Iranian coast of the Caspian Sea at four locations:  Feridoonkenar Shahed, Mahmoudabad Khoram, Lariim Azadi fishing coop, and the Shiroud River in Ramsar city. “Back-calculation” is a retrospective method of estimating the characteristics of growth of fish in terms of length and rate of growth...

2013
D.M Kennard M.J Pusey B.J Davies D. M. Warfe M. J. Kennard B. J. Pusey

The recruitment of wood from the riparian zone to rivers and streams provides a complex habitat for aquatic organisms and can influence both aquatic biodiversity and ecosystem function. The Daly River in the wet-dry tropics of northern Australia is a highly seasonal, perennially-flowing sand-bed river where surveys of river wood aggregations at the reach scale (~2 km) in 2008 and 2009 recorded ...

1999
Sébastien Brosse Jean-François Guegan Jean-Nöel Tourenq Sovan Lek

The present work describes a comparison of the ability of multiple linear regression (MLR) and artificial neural networks (ANN) to predict fish spatial occupancy and abundance in a mesotrophic reservoir. Models were run and tested with 306 observations obtained by the sampling point abundance method using electrofishing. For each of the 306 samples, the relationships between physical parameters...

2010
Daniel Pauly

The conventional view (Hoar, 1970; Liley, 1970; Harvey and Hoar, 1979) of the sequence of events which, in fish, leads to first gonadal maturation and subsequent spawning, starts with "environmental stimuli" which the brain and pineal gland process and pass on to the hypothalamus, which passes its information to the pituitary; gonadotropic hormones are then synthesized and released which leads ...

2012
Enric Sala Enric Ballesteros Panagiotis Dendrinos Antonio Di Franco Francesco Ferretti David Foley Simonetta Fraschetti Alan Friedlander Joaquim Garrabou Harun Güçlüsoy Paolo Guidetti Benjamin S. Halpern Bernat Hereu Alexandros A. Karamanlidis Zafer Kizilkaya Enrique Macpherson Luisa Mangialajo Simone Mariani Fiorenza Micheli Antonio Pais Kristin Riser Andrew A. Rosenberg Marta Sales Kimberly A. Selkoe Rick Starr Fiona Tomas Mikel Zabala

Historical exploitation of the Mediterranean Sea and the absence of rigorous baselines makes it difficult to evaluate the current health of the marine ecosystems and the efficacy of conservation actions at the ecosystem level. Here we establish the first current baseline and gradient of ecosystem structure of nearshore rocky reefs at the Mediterranean scale. We conducted underwater surveys in 1...

2015

This study was conducted to determine the cholesterol and alpha-tocopherol contents of 20 marine fish and four other seafood from the Straits of Malacca. Cholesterol and alphatocopherol contents of the fish and other seafood were determined using high-performance liquid chromatography. The results showed that most of the fish contained low amounts of cholesterol, except sixbar grouper (Epinephe...

2007
Paolo Guidetti Enric Sala

We investigated the community-wide effects of no-take marine reserves at the regional scale in the Mediterranean Sea. Reserves had general positive effects of protection on fish targeted by fishing, and variable effects on non-target species. Differences in the structure of fish assemblages (in terms of abundance of species and trophic groups) were greater between geographic locations than when...

Journal: :Current Biology 2003
Alexandra S Grutter Jan Maree Murphy J.Howard Choat

Coral reefs are one of the most diverse habitats in the world, yet our understanding of the processes affecting their biodiversity is limited. At the local scale, cleaner fish are thought to have a disproportionate effect, in relation to their abundance and size, on the activity of many other fish species, but confirmation of this species' effect on local fish diversity has proved elusive. The ...

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