| چکیده انگلیسی مقاله |
Due to the drought and water shortage of rivers in the southern basin of the Caspian Sea, especially during the release of these fish and illegal fishing of juveniles in the river, to increase the survival rate, it is better to release these fish in the river or directly into the sea. Acipenser stellatus were examined in different weights with four treatments of 0.5-0, 0.5-0, 4-9 and 9-13 salinity per thousand (ppt) and each treatment in three replications. The experiment was performed for a period of one month along with feeding with live food, preferably Daphne, Gamarus, Nereis worm with a saturation of 6 servings per day and siphon and water change. Daily losses were collected and recorded during the period. The results showed that the percentage of survival in salinities of 0.5-0 and 4-5 g / l was significantly higher than salinity of 4-9 and 9-13 g / l in the weight range of 0.5-1 g. It was 0 g (df = 3, F = 68.800, P = 0.000). Also, the percentage of survival in salinities of 0.5-0 and 4-9 g / l was significantly higher than the salinity of 13-9 g / l in the weight range of 1-3 g (df = 3, F = 7.558, P = 0.010). Survival percentage in salinities of 0.5-0 and 0.5-4 g / l was significantly higher than salinity levels of 4-9 and 13-9 g / l for weight of 3-5 g (df = 3, F = 8.933 P = 0.006). Survival percentage in different salinities in the weight range of 5-10 g showed a significant difference (df = 3, F = 68.800, P = 0.000). According to the results, it is suggested that juvenile Acipenser stellatus are first released in the estuary at salinity below weight range of 8 g / l and enter to the sea after adapting to salinity.Due to the drought and water shortage of rivers in the southern basin of the Caspian Sea, especially during the release of these fish and illegal fishing of juveniles in the river, to increase the survival rate, it is better to release these fish in the river or directly into the sea. Acipenser stellatus were examined in different weights with four treatments of 0.5-0, 0.5-0, 4-9 and 9-13 salinity per thousand (ppt) and each treatment in three replications. The experiment was performed for a period of one month along with feeding with live food, preferably Daphne, Gamarus, Nereis worm with a saturation of 6 servings per day and siphon and water change. Daily losses were collected and recorded during the period. The results showed that the percentage of survival in salinities of 0.5-0 and 4-5 g / l was significantly higher than salinity of 4-9 and 9-13 g / l in the weight range of 0.5-1 g. It was 0 g (df = 3, F = 68.800, P = 0.000). Also, the percentage of survival in salinities of 0.5-0 and 4-9 g / l was significantly higher than the salinity of 13-9 g / l in the weight range of 1-3 g (df = 3, F = 7.558, P = 0.010). Survival percentage in salinities of 0.5-0 and 0.5-4 g / l was significantly higher than salinity levels of 4-9 and 13-9 g / l for weight of 3-5 g (df = 3, F = 8.933 P = 0.006). Survival percentage in different salinities in the weight range of 5-10 g showed a significant difference (df = 3, F = 68.800, P = 0.000). According to the results, it is suggested that juvenile Acipenser stellatus are first released in the estuary at salinity below weight range of 8 g / l and enter to the sea after adapting to salinity.Due to the drought and water shortage of rivers in the southern basin of the Caspian Sea, especially during the release of these fish and illegal fishing of juveniles in the river, to increase the survival rate, it is better to release these fish in the river or directly into the sea. Acipenser stellatus were examined in different weights with four treatments of 0.5-0, 0.5-0, 4-9 and 9-13 salinity per thousand (ppt) and each treatment in three replications. The experiment was performed for a period of one month along with feeding with live food, preferably Daphne, Gamarus, Nereis worm with a saturation of 6 servings per day and siphon and water change. Daily losses were collected and recorded during the period. The results showed that the percentage of survival in salinities of 0.5-0 and 4-5 g / l was significantly higher than salinity of 4-9 and 9-13 g / l in the weight range of 0.5-1 g. It was 0 g (df = 3, F = 68.800, P = 0.000). Also, the percentage of survival in salinities of 0.5-0 and 4-9 g / l was significantly higher than the salinity of 13-9 g / l in the weight range of 1-3 g (df = 3, F = 7.558, P = 0.010). Survival percentage in salinities of 0.5-0 and 0.5-4 g / l was significantly higher than salinity levels of 4-9 and 13-9 g / l for weight of 3-5 g (df = 3, F = 8.933 P = 0.006). Survival percentage in different salinities in the weight range of 5-10 g showed a significant difference (df = 3, F = 68.800, P = 0.000). According to the results, it is suggested that juvenile Acipenser stellatus are first released in the estuary at salinity below weight range of 8 g / l and enter to the sea after adapting to salinity.v |