sperm morphology, biochemistry and physiology were compared between siberian sturgeon Acipenser baerii and sterlet A. ruthenus in the present study. We observed wide morphological variations between spermatozoa of the two species. the average length of the spermatozoon head was 7.01 and 5.14 μm in A. baerii and A. ruthenus, respectively. Significant differences were observed in terms of Na+, k+...

Aquatic organisms present, not only simple sources of accumulated metal, but can interact with metals, altering their toxicity. Due to exposition of biosphere with metals, organisms have developed various defense mechanisms to protect themselves against adverse effects of these ions and their compounds. Metallothionein (MT) is one of that which represents a critical mechanism for detoxification...

this study was carried out to evaluate the effect of commercial live bakery’s’ yeast( saccharomyces cerevisiae ), (marketed as amax), on growth and survival of persian sturgeon( acipenser persicus) larvae (74.9 ± 9.7mg) during 30 days. sturgeon larvae were fed on daphnia magna enriched at three suspensions of yeast, amax, (0, 50, 100, and 150 mg yeast per litter). the feeding level was 30 perce...

the effect of starvation and re-feeding was investigated on growth, hematology and biochemical parameters in juvenile persian sturgeon (acipenser persicus). three hundred and seventyfive fish (108±0.63 g) were divided into five feeding groups. the control group (c) was fed to satiation three times a day during the experiment. the four groups were starved for 1 (w1), 2 (w2), 3 (w3), and 4 (w4) w...

The specific objectives of this study were to determine the optimum feeding frequency in juvenile GIFT (Genetically Improved Farmed Tilapia) strain of Nile tilapia (Oreochromis niloticus), for growth rate, body composition, and gastric evacuation, as well as to investigate the passage of a single meal through the stomach in order to establish gastric evacuation rate. Six treatment groups of juv...

This study was performed to investigate the effects of feeding rates on growth performance, feed conversion and body composition of juvenile snow trout (Schizothorax zarudnyi). For this purpose, fish with an initial body weight of 2.17±0.1 g were fed a commercial diet (40% protein, 3.8 Kcal g-1 diet) at five ration sizes of 2%, 4%, 6%, 8% and 10% of their body weight per day, for 60 days. The f...

This study was performed to investigate the effects of feeding rates on growth performance, feed conversion and body composition of juvenile snow trout (Schizothorax zarudnyi). For this purpose, fish with an initial body weight of 2.17± 0.1 g were fed a commercial diet (40% protein, 3.8 Kcal/g diet) at five ration sizes 2%, 4%, 6%, 8% and 10% of their body weight per day, for 60 days. Feeding t...

The freshwater angel fish (Pterophyllum scalare Schultze, 1823) is South American cichlid become very popular among aquarists. There is little information on their culture and aquarium husbandry. In this study growth performance and survival rate of angelfish subjected to different feeding frequencies were evaluated. Four groups of angel fish juveniles (0.87 ± 0.01 g; 3.98 ± 0.08 mm) were fed e...