نوع مقاله : بوم شناسی
نویسندگان
1 گروه محیط زیست و انرژی، دانشکده منابع طبیعی و محیط زیست، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران
2 گروه تنوع زیستی و مدیریت اکوسیستم های پژوهشکده علوم محیطی، دانشگاه شهید بهشتی، تهران، ایران
3 گروه زیست شناسی و زیست فناوری دریا و آبزیان دانشکده علوم و فناوری زیستی، دانشگاه شهید بهشتی، تهران، ایران
4 گروه شیلات و محیط زیست، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Age structure and growth characteristics of the Schizothorax pelzami (Kessler,1870) in the two different habitate (Frizi river and Cheshmeh Sabz lake in Khorasan province) were studied from January, 2009 through January,2010. Age and growth variables were determined by examining 495 opercular bones, 261 samples from the river habitat and 234 species from the lake habitat of the S.pelzami populations from specimens ranging between 69 and 274 mm total length. The instantaneous growth rate of young (one and two year old) S. pelzami in the river habitat (mean higher temperature) was observed higher than the population living in the lake habitat (mean lower temperature).The results also showed that S. pelzami has living longer in the lake habitat. Almost all of S. Pelzami had reached maturity in 2-3 year-old in River site but age maturity of this species in lake site was 4 and 5 years old. Von Bertalanffy growth parameters showed that L(¥)in the lake population(♂464.66, ♀514.70)was higher than river population(♂303.15 , ♀ 456.92). Growth performance index(φ') was calculated in the lake habitat (♀9. 386, ♂9.225) and in the river habitat (♀9.253, ♂9.074). Overcoming the sex ratio in the river habitat was related to the male genus and in the lake habitat to the female sex.results of this study show that differences in habitat conditions,especially water temperature and geographical location of two habitats, have led to the formation of different strategies in age structure and pattern of growth in each population.
کلیدواژهها [English]