animal
bita dehghani; yazdani yazdani; mastooreh doustdar; Seyed Ahmadreza Hashemi; ehsan damadi
Abstract
Introduction:The study of fish in aquatic ecosystems is important from many aspects, including ecology, behavior, protection, and management of water resources, exploitation of reserves, and their cultivation the genus Acanthopagrus includes species with high economic importance and many challenges in ...
Read More
Introduction:The study of fish in aquatic ecosystems is important from many aspects, including ecology, behavior, protection, and management of water resources, exploitation of reserves, and their cultivation the genus Acanthopagrus includes species with high economic importance and many challenges in their classification. The reason for this is the morphological similarity between a large number of their species. Methods:The purpose of this study is to investigate the morphological diversity of 5 species of Acanthopagrus fishes using traditional morphometry, truss system and geometric morphometry in the Gulf of Oman and the Persian Gulf. In the present study, in traditional morphometry17 morphometric charactris and 10 meristic charactris were measured . In the geometric method, 17 landmarks were placed on the images, and then morphological differences between species were subjected to principal component analysis (PCA) and canonical variate analysis (CVA). Results:In the traditional approach,morphometric charactris show the separation of A. arabicus species from two species, A. bifasciatus and A. catenula, meristic charactris performed much better than quantitative charactris and separated most of the species from each other. The number of lateral line scales and the number of scales above the lateral line showed the greatest role in the separation of the members of this genus. Also, the truss approach separated A. catenula and A. bifasciatus species from other species. The geometric method shows the separation of two species, A. arabicus and A. sheim.
Seyed Ahmadreza Hashemi; mastooreh doustdar
Abstract
Fish species overexploited (overfished) level of Iran (Southern waters from 1997 to 2017) was assessed based on the catch maximum sustainable yield (CMSY), R-software, Bayesian approach and Monte-Carlo simulation. Average of demersal fish catch in Iranian southern waters during this period was 141221 ...
Read More
Fish species overexploited (overfished) level of Iran (Southern waters from 1997 to 2017) was assessed based on the catch maximum sustainable yield (CMSY), R-software, Bayesian approach and Monte-Carlo simulation. Average of demersal fish catch in Iranian southern waters during this period was 141221 tons (95% Confidence interval (C.I) = 141131 to 141612 tons) and mean catch was significantly increased over the past two decades (R = 0.90, P <0.05). Also, for this study period, average of demersal fish catch in the northern waters of the Oman Sea (Iran, Sistan and Baluchestan province) was 38776 tons (95% Confidence interval (C.I) = 38845 to 38706 tons) and mean catch significantly increased over the past two decades (R = 0.94, P <0.05). Total overfished (weight) level of southern water was more than 31 percent. Demersal fish overfished in Iranian southern water and in the northern waters of the Oman Sea (total weight level) were exceeded 45 percent and 75 percent, respectively. Due to the existing situation, it seems that the amount of overexploited (overfished) is not in favorable condition and further decrease in exploitation ratio and fishing effort are proposed.
