The coexistence of competing species relies on niche partitioning. Competitive exclusion is likely inevitable at high niche overlap, but such divide between competitors may be bridged if environmental circumstances displace competitor niches to enhance partitioning. Foraging-niche dimension can be influenced by environmental characteristics, and if competitors react differently to such conditio...

 Concentration of heavy and toxic metals Cu, Zn, Cd, Pb and Hg were determined in liver and muscles of Rutilus frisii kutum and their relationships with growth parameters (length, age, condition factor) and hepatosomatic index were examined. Thirty-six fish samples were collected from February through March 2009 caught by beach seine in the southwest parts of the Caspian Sea. Atomic ab...

The growth and mortality coefficient of Rutilus frisii kutum, were estimated using length frequency data collected in southern waters of the Caspian Sea during October 2008 to April 2009. The following population parameters were evaluated: length-weight relationship, W = 0.004L 3.258, (r= 0.976) Von Bertalanffy growth constants, W∞ (g) = 4192.3, L∞ (cm) = 70.45, K = 0.2, per year t0 = −0.75 tot...

This study proceeds to extract collagen from the skin of Rutilus  kutum, one of  the main and economical species of the Caspian Sea. Acid-soluble collagen (ASC) from the skin of R. kutum was extracted and characterized by SDS-PAGE, FTIR and UV spectrophotometry. Based on the data from the SDS-PAGE and the composition of amino acid, it was probable that the obtained collagen classified as type I...

Protein synthesis by a rabbit reticulocyte lysate is inhibited by the haemagglutinating lectins from Momordica charantia and Crotalaria juncea seeds and from the roe of Rutilus rutilus, and by a commercial preparation of the mitogenic lectin from Phytolacca americana. The haemagglutinins from the seeds of Ricinus communis and of Vicia cracca acquired inhibitory activity after their reduction wi...

Caspian kutum, Rutilus frisii kutum, is one of the most commercially important fish species in the Caspian Sea, but there are few reports about the endocrinology of induced spawning in this fish. In the present study, 54 individuals of female broodstocks of Kutum were studied for quantity and quality of propagation index, during March and April 2007. Hormone treatments include: LHRH-A2 (1 ?g kg...

The growth and mortality coefficient of Rutilus frisii kutum, were estimated using length frequency data collected in southern waters of the Caspian Sea during October 2008 to April 2009. The following population parameters were evaluated: length-weight relationship, W = 0.004L 3.258, (r= 0.976) Von Bertalanffy growth constants, W∞ (g) = 4192.3, L∞ (cm) = 70.45, K = 0.2, per year t0 = −0.75 tot...