جستجوی مقالات مرتبط با کلیدواژه « population dynamic » در نشریات گروه « زیست شناسی »

The present study was carried out in two Station in Costal of the Khuzestan province (including Abadan, and Hendizan) using the commercial catch data. This project one year during 2007-2008, in addition over 2300fish caught was biometry. The growth and mortality parameters of Silver pomfert, infinity length, L∞: 35.5., growth curvature, K: 0.56., length in zero time, t0: - 0.32., total mortality, Z: 3.06., natural mortality, M: 1.07., fishing mortality, F: 1.99 and Exploitation ratio, E: 0.65 respectively were estimated. By used analysis method, Y'/R = 0.019, B'/R=0.10, Exploitation rate, U: 0.61, MSY= 440 T and MCY=290 T were estimated respectively. Result in this study showed exploitation ratio the Silver pomfert stock is over fishing and decrease exploitation ratio proposed.

Study was conducted to determine some biological characteristics and population dynamic of Platycephalus indicus were studied during one year from May 2011 to March 2012 in the coastal waters of Bandar Abbas. A total of 1106 samples were collected. Also, each month 35 fish was chosen and transferred to the laboratory for evaluation of spawning season. The ages of 279 specimens were determined by sectioned otoliths. The ages of the females were estimated to be between 1 to more than 7,while the ages of the males were from 1 to more than 4.The relationship between weight and length (Total length) can be expressed as W=0.004L3.16 35 for male and W = 0.0042L3.1293 for female. This equation indicates that keeled mullet has allometric growth. The values for natural mortality (M) resultant coefficient were M = 0.886 year-1 for females and 0.736 year-1 for males, and the estimated Z values were 1.43 year-1 for females and 1.62 year-1 for males. These ages were then ®tted to the von Bertalanffy growth equations. Equations obtained were Lt = 43.4 (1-exp(-0.45 (t .32))) for males, and Lt = 63 (1-exp(-0.50(t 0.30))) for females.