The effect of methyl farnesoat on some reproductive efficiency parameters of male Astacus leptodactylus

In this master's thesis, it was aimed to increase the reproductive efficiency (eg sperm number) of male A. leptodactylus with the injection of hormone (methyl farnesoate, MF). In this study it was also aimed to investigate the changes in hemolymph MF levels and hepatopancreas, hepatosomatic index, protein and amino acid structure in different doses of MF injected crayfish. For this purpose, control group (D0) no injection group, the control group (D1) without MF injection only 20 ML etanol+30 ML 0,85 % salt solution and the D2, D3 and D4 experimental groups with MF were prepared at 250, 500 and 1000 ng/g body weight doses. At the end of the study, the sperm number of the crayfish were determined and the weight of the reproductive system, testis and vas deferens were measured. Also gonadosomatic index, testis index and vasdeferens index values were calculated. The results showed that MF injection significantly increased sperm number, reproductive system weight and values of testis index, vasdeferens index and gonadosomatic index in this species (P < 0.05). The best results were obtained from crayfish exposed to D4. The lowest sperm number was obtained from the control group with 5.6x106 and the highest sperm count was 8.20x106 with D4 group. On the other hand, as a result of the research, it was determined that the hemolymph MF level did not differ significantly between the groups. While the amount of protein in the hepatopancreas was determined as 28.24 mg/g in the control group, this value was significantly higher in the D4 group (37.8 mg/g) (P < 0.05). It was also found that there was no significant difference between the experimental groups in the amount of protein in hepatopancreas (P > 0.05). In addition, the findings showed that hepatosomatic index increased significantly with MF injection (P < 0.05). 18 amino acids were detected in the hepatopancreas. Arginine and proline were found to be the most abundant amino acids in all groups, while the lowest levels of alanine were found and there was no statistical difference between the groups (P > 0.05). 19 fatty acids were determined in crayfish. There was no statistically significant difference between the fatty acids between the control and MF groups. In conclusion, it was determined that the reproductive efficiency of male A. leptodactylus could be significantly increased by MF injection.