نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه شیلات، دانشکدة منابع طبیعی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج. ایران
2 دانشیار گروه شیلات، دانشکدة منابع طبیعی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج. ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Considering the importance of studying inland fishes, especially endemic fishes, some morphological characterization, length-weight relationship, and condition factor of Namak chub (Squalius namak) in the Jajrood protected river were investigated at three stations. To investigate the morphometric variation, 13 landmarks were placed on 2D images using TpsDig2 software, and 4 distance features were measured using ImageJ software. The equation W = aTLb was used to calculate the length-weight relationship, and the formula K = (W/Lb) × 100 was used to calculate the condition factor. Past, morphoJ, and R softwares were utilized to analyze the data. Based on the landmark displacement patterns, the most significant landmark displacements were related to the pectoral, dorsal, ventral (pelvic) fins and snout of the fish. The total length-weight relationship for all fish was obtained as W=00048L3.24 with a correlation coefficient of R2=0.88. In this study, the condition factor (CF) of the S. namak was calculated in the range of 0.032 to 0.19, which indicates very bad to bad living conditions for the fish in the Jajrood river. The total length and total weight of the studied specimens were in the range of 7.82 to 37.67 cm and 48. to 44.94 g, respectively. According to the findings, the studied species did not have a suitable growth pattern, in other words, this fish does not grow equally in all body dimensions (allometric). The most important causes can be considered to be unsuitable habitat conditions, including the small size of the ecological niche and lack of food.
کلیدواژه‌ها [English]
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