amirhushang bahri

The nutritional value and special properties of Artemia have led to its use as a food and biological model in aquaculture. L-Carnitine supplementation stimulates the oxidation of fatty acids, increases nitrogen retention and resistance to environmental stress, and L-Arginine nutritional supplementation is effective in protein synthesis, nitric acid and growth hormone growth and survival. In this study, the effect of Nanochloropsis oculata micro algae enriched with L-carnitine and L-arginine supplements on growth, environmental stress, absolute fecundity and saturated fatty acid profile in Artemia feransiscana was investigated. L-carnitine and L-arginine were applied separately at concentrations of 0, 1, 10, 100 and 1000 mg/l. Artemia cysts under special hatching conditions and Napolius were fed with N. oculata microalgae with two states, enriched conditions and without enrichment (control treatment) separately in 30 days. The results were compared and it was shown that the highest saturated fatty acid (SFA) with nutritional treatment L-carnitine 10 mg/l and the lowest was in the control treatment. The highest mortality percentage of ammonia shock was related to rich treatment with 1 and 100 mg/l L-carnitine which showed a significant difference with the control treatment (p<0.05) and the lowest was related to 1 mg/l L-arginine treatment and control treatment. In hypoxia shock, the highest mortality percentage was observed in the diet with L-carnitine 1 and L-arginine 1 and 100 mg/l and the lowest in the diet with L-carnitine 10 mg/l, all of which showed a significant difference with the control treatment (p<0.05). In  adult Artemia breeders,  the lowest quality indicators  were related to L-carnitine treatment at all doses except 1000 mg/l and the highest were related to L-arginine treatment except 100 mg/l plus 1000 mg/l. L- carnitine that showed a significant difference with the control treatment (p<0.05) .The highest amount of absolute fecundity is related to the nutritional treatment rich in L-arginine 1000 mg/l and the lowest is the control treatment, which shows the positive effect of both supplements on increasing the absolute fecundity. Overall, the results showed that the use of the mentioned nutritional supplements with N. oculata microalgae in A. franciscana nutrition in specific doses can be effective in increasing production and quality in the aquaculture industry. Therefore, according to the environmental stress conditions, improving the fecundity performance and achieving a higher quality index, the optimal doses of each supplement can be used.

Zooplanktons are important elements of an aquatic ecosystem such as ponds. They are involved in rotation of materials, control of algae communities and microbial production. The aim of this study was to investigate the frequency and identification of zooplankton in sturgeon fish ponds of Shahid Beheshti aquatic reproduction and reconstruction complex and their relation with physical and chemical factors of water. Five ponds were studied. Physical factors such as dissolved oxygen, temperature, pH and saturation, and chemical factors such as nitrite, nitrate, ammonia and orthophosphate were measured twice a week with 3 replicates. A total of 22 genera were identified from 4 branches of Cladocera (5 genera), Copepoda (3 genera), Protozoa (2 genera) and Rotifera (12 genera) in the studied ponds. The highest variety and abundance were found in Rotifera and Copepoda respectively. Nauplius, Daphnia and Cyclops had the highest percentage of zooplankton with 46%, 25% and 15% respectively. The results of measurement of physical and chemical factors of water indicated optimal water conditions of the ponds and only the orthophosphate factor was higher than the limit. There was a significant negative correlation between pH and orthophosphate factors (P> 0.05). There was a significant positive correlation between cladocera and orthophosphate factor as well as zooplankton and nitrate factor in all ponds (P<0.01). Based on the results, the ponds were in optimum condition in terms of physical and chemical factors and zooplankton population and only the orthophosphate factor was above the permissible limit which could be controlled by proper management.

Cichlasomaseverum sp. is one of the most beautiful ornamental freshwater fish that is a favorite of many breeders in Iran. This fish is very strict in selecting pairs after choosing the perfect pair, if the availability of suitable environmental conditions, these fish can reproduce in the aquarium environment. Unfortunately, hatchability and survival of Severums' larval is very low. In this study, use of hormone therapy with carp pituitary extract (3 mg/KgBW and 5 mg/KgBW) and gonadotropin-releasing hormone (10 µg/KgBW and 20 µg/KgBW) with domperidone as anti-dopamine (5 mg/KgBW and 10 mg/KgBW, respectively) in the induced egg lay Severum fish was studied. Then, the effects of hormone therapy on physiological response spawners, fecundity, hatchability and larval survival have been investigated. Based on the results, although the fish are spawning after hormone administration to induce ovulation and stimulate, reproductive efficiency has reduced in treated fish when compared with control group (P<0.05). This phenomenon may be due to stress and hormone administration during manipulation and injection or inappropriate hormone concentrations is used in hormone therapy.