Study of Tagging Effects on Surviving Rate of Caspian Trout (Salmo trutta caspius) Fries Before Releasing to Natural Habitat

Abstract

Study of tagging effects on survival rate of Caspian trout (Salmo trutta caspius) fries before releasing to natural habitat was a part of a large research plan on conservation and restoration of Caspian trout stocks in the Southern Caspian by Coldwater Fishes Research Center. Catching brooders, propagation, larvae and juvenile rearing were carried out in Southern coasts and rivers of Caspian sea and in shahid Bahonar propagation center in Kelardasht, Mazandaran (North of Iran) in autumn 2012. 150 fries for each treatment (5, 10 and 20 g fries and Plastic T tag, elastomer tag and control treatments) anesthetized, weighed (g), measured (mm), tagged, disinfected and introduced to cement ponds. Fries were kept and fed for 5 days and their behavior and responses to food, infection of wound and mortality were recorded. No mortality were observed in all treatments, fries were shocked for few hours after handling and did not take food but they started to feed from the first day after tagging and there was no infection in macroscopic observation of wound.