Showing 2 results for GH. Azari Takami
Gh. Azari Takami, M. Amini, M. R. Naghavi,
Volume 10, Issue 2 (summer 2006)
Abstract
The masculinization effects of 17α-methyltestosterone were investigated on the two developmental stages of guppy (Poecilia reticulate), namely, newly born fry and gravid females. The first group was treated with two doses of androgen, (30 and 60 mg/kg food), each for a period of 15 and 30 days and the second group (gravid females) was treated with the food doses of 400, 450 & 500 mg/kg in a 10 day duration prior to parturition. After three months, the first group masculinization ratio of 62.14% was attained only in 60 mg/kg at three-day long treatment and other treatments had no significant effect on masculinization. In this group all the treated fish developed male secondary sexual characteristics after 3 or 4 weeks. However, the above-mentioned characteristics disappeared gradually when hormone therapy was stopped. In the second group, all the treatments were significantly different from control group. 450 and 500 mg/kg treatments had the highest masculinization percentage (90.82 and 97.07, respectively) but the differences were not significant. Also there were 9.18% females in 450 mg/kg treatment and 2.93% intersex in 500 mg/kg treatment. But the so-called group mortality was higher and fecundity lower than those in the control group. Finally, it should be noted that hormonal treatment had not any significant effect on masculinization of newly born fry and with the regard to the effect of 450 mg/kg treatment on masculinization and mortality percentage, it can be introduced as the best treatment.
M. Yahyavi, Gh. Azari Takami, Gh. Vosoughi,
Volume 10, Issue 4 (winter 2007)
Abstract
Stress tests are commonly applied in shrimp hatcheries to estimate the quality of postlarvae to be used during growout. The highest larval survival rate during culture and in shrimp stress tests has been reported when specimens are offered a diet containing high levels of highly unsaturated fatty acids ( HUFA ) . Also vitamin C has positive effect to resistance and survival of larvae . In this study in postlarvae stage 1 in the salinity stress tests (10 and 20 ppt ) the highest survival rate was observed in treatment 3 ( 56.667 % and 90.00 % ) which was enriched with highly unsaturated fatty acids and vitamin C . As for the second, treatment 2 ( 43.333 % and 76.667 % ) which was solely enriched with highly unsaturated fatty acids showed significant differences at a level of ( P < 0.05 ) with treatment 3 . The difference between these two treatments and treatment 1( larvae fed rotifers cultured on Chlorella sp. ) and control ( larvae fed newly hatched Artemia nauplii ) was also significant . No significant difference was observed in formalin stress test ( 100 ppm ) in this stage between treatments 3 ( 86.667 % ) and 2 ( 80.00 % ) which shows the highest survival rate . But difference between them with treatment 1( 60.00 % ) which was unenriched and control ( 53.333 % ) was significant . Also, in postlarvae stage 5 in the salinity stress tests (10and20 ppt) the highest survival rate was observed in treatment 3 ( 56.667 % and 83.333 % ) and later treatment 2 ( 40.00 % and 70.00 % ) which showed significant difference . In this stage , the survival rate the treatment control ( 60.00 % and 86.667 % ) and treatment 3 showed no significant difference but they showed significant differences with treatment 1 and 2 .The lowest survival rate was observed in treatment 1( 26.667 % and 56.667 % ) . And the highest survival rate was observed in formalin stress test ( 100 ppm ) in this stage in treatments control , 3 and 2 ( 76.667 % , 73.333 % and 70.00 % ) among which there were no significant differences . However, the difference between these three treatments with treatment 1 ( 53.333 % ) was significant .
