Study on three groups of algae (Cyanophyta, Chlorophyta and Bacillariophyta) in the feeding of Hypophthalmichthys molitrix

In order to study phytopague fingerlings feeding in fish ponds, simultaneously to the beginning of warm season and cultivation, fingerlings of ۳-۵ gram from ۳ponds in Mazandaran province were captured, fixed with formalin, then transferred to the plankton determination laboratory of Caspian Sea ecologic institute. Based on this study, essential differences of digestion were observed following to the source of nutrition and the most difference were considered in digestion of Chrysophytes, Cyanophyta and Chlorophyta. Base on the results of this study we propose to make more studies on fertilization and the proportion of different fertilizers in fish ponds in order to obtain easily digestible phytoplankton thus increase in fish exploitation. Also, Bacillariophyta contain ۵۶ percentage of beginning of digesting system and ۲۰ percentages in the end of digesting system. Chlorophyta and Cyanophyta plug at the end of the intestine had a higher percentage than the beginning of the intestine and indicates that the industry is less digestible, while the branch Cyanophyta had the highest concentration in the water swimming pools (۸۴۴۲۹۸۵ pcs per cubic meter). Comparison of phytoplankton pool and intestinal contents with Chi-square test showed that the difference between the frequency difference between the frequency of phytoplankton pool and the beginning of the colon and intestinal contents at the beginning and end of the intestine showed no significant difference. Base on the results of this study we propose to make more studies on fertilization and the proportion of different fertilizers in fish ponds in order to obtain easily digestible phytoplankton thus increase in fish exploitation.

Keywords:

Silver carp fry , Feeding , Hypophthalmichthysmolitrix , Mazandaran , Phytoplanktons