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Showing 2 results for Harsij
Hossein Jahanatighi, Mohammad Golizadeh, Rahman Patimar, Mohammad Harsij, Volume 11, Issue 4 (winter 2020)
Abstract
Today, freshwater resources, including rivers and lakes, are considered as an important source of water at risk of pollution from human activities, such as the outflow of fish. In this study, the effect of two species of Phragmites australis and Cyperus rotundus and their effects on water quality changes such as nitrate, ammonia, and phosphate in the Breeding of common carp were used. In this regard, 90 species of both species, reed plants with initial weights of 100 ± 10 grand nut sedge strain with an initial weight of 30 ± 5 in six channels of 120 liters (30 plants per channel) were treated. One hundred kilograms of common carp with a mean weight of 20-2.3 g was introduced into a tank with a capacity of 1000 liters dewatering during the 42-day trial period. The results showed that the average final weight of fish was 35 ± 5 and the mean weight of each plant was 50 ± 500 g and the mean weight of the nutsedge plant was 10 ± 100 g. Water quality analysis showed that there was a significant difference between the input of fish tanker water and the output water of plant cultivars (P <0.05). Based on the reduced rate of high concentrations, the best remaining time was selected in the fourth week. Also, the results showed a significant difference between the outputs of the treatments in terms of improving the quality factors of water at a probability level of 5%. On the other hand, with a significant interaction between treatment output over different periods can be understood that the plant material selected as the filters have a high potential to absorb nitrates, nitrite, ammonium, and phosphates.
Eisa Hajiradkouchak, Rahman Patimar, Mohammad Harsij, Rasoul Ghorbani, Volume 11, Issue 4 (winter 2020)
Abstract
In this study, age and growth parameters of Prussian carp Carassius gibelio were examined using 222 specimens from the Boostan dam lake and 238 specimens from the Alakoli reservoir. Sampling was carried out monthly from February to September 2015. The ratio was 1:0.13 and 1:0.09 in the study population of Boostan Dam Lake and Alakoli reservoir, respectively. Age determination by scales showed six age groups (1+-6+) for females and three age groups (1+-3+) for males in the Bostan Dam Lake and five age groups (1+-5+) for females and four age groups 1+, 2+, 4+ and 5+ for males in the Alakoli reservoir. The total size distribution varied from 3.3 to 20.6 cm in length and 0.83 to 141.12 g in weight and from 4.3 to 19/6 cm in length and 1.67 to 114.65 g in weight in the Boostan dam lake and Alakoli reservoir respectively. The growth pattern was isometric in males and negative allometric for both females and population in the Boostan Dam Lake and isometric in males and positive allometric for both females and population in the Alakoli reservoir. The parameters of von Bertalanffy growth fit the mean observed total lengths-at-age for each sex separately and were estimated as (L∞= 574.17 cm, k = 0.07 year -1, t0= -0.10 year for females, L∞= 338.43 cm, k = 0.15 year-1, t0= -1.04 year for males, and as L∞= 299.06 cm, k = 0.18 year -1, t0= -0.34 year for combined sexes in the Boostan dam, L∞= 4344 cm, k = 0.01 year -1, t0= -0.12 year for females, L∞= 3177 cm, k = 0.01 year-1, t0= -0.18 year for males, and as L∞= 2526.15 cm, k = 0.04 year -1, t0= -0.40 year for combined sexes in the Alakoli reservoir. The instantaneous growth rate was 1+-2+ ages for population in both regions. Condition factor showed that in the Boostan Dam Lake, the highest value was observed in June and August for females and the lowest in March for males and in the Alakoli reservoir, the highest condition factor was in May for females and the lowest in May for males. This results showed that these values differ in our study with other studies in this field that can be attributed to environmental differences.
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