S. A. R. Hashemi; S. A. Taghavimotlagh; R. Ghorbani; A. Hedayati
Volume 3, Issue 1 , March 2013, , Pages 1-6
Abstract
During this study from December 2009 to November 2011, 363Deep flounder fish were caught and their weight and length were measured. The caught fish included 18 males, 200 females and 155 immature fishes. The mean, maximum and minimum total lengths were 264 ± 57 (mean ± SD), 415 mm and 115 ...
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During this study from December 2009 to November 2011, 363Deep flounder fish were caught and their weight and length were measured. The caught fish included 18 males, 200 females and 155 immature fishes. The mean, maximum and minimum total lengths were 264 ± 57 (mean ± SD), 415 mm and 115 mm respectively. The mean, maximum, and minimum total weights for this species were 238 ± 150 g, 827 g and 14 g respectively. The calculated length-weight relationships were W=0.000007FL3.09 (n=200, R2= 0.96) for the female, W=0.00002FL2.90 (n=18, R2=0.94) for the male and W=0.000009FL3.04 (n=363, R2 =0.96) for total fish. With a verified calculated b as 3 Student t-test showed no significant difference between calculated b and 3 (P>0.05), demonstrating that the growth pattern is isometric. Population parameters calculated for total fish were L∞= 42 (cm); K= 1 (year-1); t0= -0.14 and Ф’= 3.24. Based on the results, this species is classified as mediate vulnerable group fish.
R. Gilanshahi; S. A. Taghavimotlagh; F. Kaymaram; S. M. R. Fatemi; Gh. Vosooghi
Volume 2, Issue 3 , August 2012, , Pages 197-202
Abstract
The growth parameters, mortality rates and exploitation population dynamic parameters and exploitation rate of Psettodes erumei were assessed between July 2010 to June 2011 using length frequency analysis. The data were collected from landing sites of Jask, Bandar Abass, Kong and Qeshm Hormozgan province ...
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The growth parameters, mortality rates and exploitation population dynamic parameters and exploitation rate of Psettodes erumei were assessed between July 2010 to June 2011 using length frequency analysis. The data were collected from landing sites of Jask, Bandar Abass, Kong and Qeshm Hormozgan province waters. Using total weight (W) and total length (TL) data, the length- weight relationship of this fish species was described as W=00037/L33652/ pertaining to alometric growth. Asymptotic length (L∞) = 74.55 cm, coefficient growth (k)= 0.23 year-1, t0 = - 0.61, longevity (tmax)= 12.43 years and the growth performance index (Φ’)= 3.10 were estimated through the ELEFAN I routine and other modules from the FISAT program. Total mortality (Z), natural mortality (M), and fishing mortality (F) were then calculated as 1.2 year-1, 0.51 year-1, 0.69 year-1 respectively. Although, the estimated exploitation ratio (E= 0.57) was well fitted with the optimum level, careful examination of exploitation rate (U) revealed that the major part of the stock (> 48% length frequency) is being fished out of the defined optimum length. Consequently, the need to improve fishing methods seems mandatory in the future to ensure that total landings do not exceed 525 tons predicted maximum constant yield (MCY).