نوع مقاله : مقاله پژوهشی
1 گروه شیلات، پردیس کشاورزی و منابع طبیعی کرج، دانشکده منابع طبیعی، دانشگاه تهران.
2 واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران.
عنوان مقاله [English]
This research was conducted to study the ontogeny of visual structure and retina of Sterlet (Acipenser ruthenus) during early development from hatching up to 50 DPH (day post hatching). For this purpose histological sections of eye during this period were prepared using paraffin method and stained by hematoxilin-eosin. At hatching time, the retina was not differentiated and differentiation of eye layers were starts from 2 DPH. Main developmental changes in Sterlet eye were occurred at 3 DPH. At this time, eye wall, lens, iris, choroid layer, scleral layer, cornea and vitreous humour were observable. In addition, differentiation of the retina with a high intensity of cone visual cells was observed at 3 DPH. The retina was developed as several layers with increasing intensity of rod visual cells at 9 DPH. Upon 25 DPH, most of visual structures and retina were fully developed and eye structure was similar to those of adult fish. The results revealed that ontogeny of visual structures and cells is occurred in accordance with changes in biological demands and habitat changes i.e. beginning of exogenous feeding and benthic life style of Sterlet.