To identify a simple tool for quick evaluation of quality of endangered Caspian brown trout, Salmo trutta caspius eggs, the changes of pH (both in ovarian fluid and fertilization water), turbidity (both in ovarian fluid and fertilization water), fertilization and eyeing rates were investigated in ovarian fluid samples containing perfect eggs as well as different concentrations of broken eggs. The pH of ovarian fluid and water as well as fertilization and eyeing rates decreased significantly (P<0.05) with increasing of broken eggs in ovarian fluid. In contrast, the turbidity of ovarian fluid and water as well as mortality rate of eggs increased significantly (P<0.05) with increasing of broken eggs in ovarian fluid. Also, significant correlations (P<0.01) were found between measured parameters as follow: pH of ovarian fluid vs. pH of water and fertilization and eyeing rates; turbidity of ovarian fluid vs. turbidity of water; turbidity of ovarian fluid and water vs. fertilization and eyeing rates. Our results conclude that pH and turbidity of ovarian fluid and water effectively influence on efficiency of artificial propagation. Therefore, these could be used as two simple tools for quick evaluation of quality of Caspian brown trout eggs during artificial reproduction in the hatchery.

No abstract

This study was conducted to determine the effects of hormone treatment on testis structure in Barbus sharpeyi, as well as the morphology of sperm examined by scanning electronic microscopy (SEM). Male B. sharpeyi were divided into three groups (three fish per group) and injected with luteinizing hormone -releasing hormone analogue (LHRH-A 2 ) or carp pituitary extract (CPE). The first and second groups were treated with 10 lg kg À1 LHRH-A 2 and metoclopramide (MET), and their testis were sampled pre-and Poststripping respectively. The third group received 2 mg kg À1 CPE and were killed pre-stripping. Based on the histological results obtained, the testicular connective tissue of the lumen was thicker, and seminal vesicles were of a lower volume, in fish injected with CPE in comparison to the other groups. After treatment with LHRH-A 2 and MET, not all spermatozoa within the testis were ejaculated, and only a small amount of sperm was obtained by abdominal stripping. The highest and lowest diameters of connective tissue within lobules were observed in fish receiving CPE and LHRH-A 2 treatments respectively. There was a significant difference (P < 0.05) in lobule space between the fish injected with the CPE and the fish injected with the LHRH-A 2 and MET. The SEM results revealed that the spermatozoa of B. sharpeyi were composed of a spherical to elliptical head, a cylindrical midpiece, and a lengthy flagellum. In conclusion, it was found that injection with LHRH-A 2 and MET improved the spermatogenic process in comparison to injection with CPE.