Fisheries

In this study, the embryonic development of the eggs in the Mastacembelus mastacembelus (Bank & Solender, 1794) was examined. At the same time, possibilities of artificial breeding through artificial insemination were investigated. Artificial insemination was achieved by mixing the eggs of the mature female and sperm of the mature male samples caught with gill nets (22 × 22) in Ataturk Dam Lake in Turkey. To this end, first in a Petri dish (100 × 20), the testes were cut into small pieces with a lancet and the mixture of sperm–testes-tissue was obtained. The fertilization rate of the eggs was found to be 80%. The diameter of the eggs ranged from 2.015to 1.147 mm. The perivitelline space formed 0.5 h after insemination. The first cleavage occurred at the animal pool 4 h after insemination. The oil droplets had fused to a single droplet 19 h after insemination. The blastoderm became an embryonic shield 30 h after insemination. The blastoderm covered almost half the egg 40 h after insemination and embryonic body was formed. The blastoderm covered almost the whole egg 50 h after insemination. Some somites were discernible 59 h after insemination. The embryonic body reached two-third of the circumference of the egg 70 h after insemination. The tail bud began to separate from the yolk 77 h after insemination. A newly hatched larva was observed at 85 h after insemination.

This study was carried out to determine the milt quality in male Mesopotamian spiny eel (Mastacembelus mastacembelus; Bank & Solender in Russell, 1794) during spawning season. Review was performed using 58 M. mastecembulus males captured from Atatürk Dam Lake in Turkey. Milt samples were collected and evaluated daily during sampling period. In collected milt, volume of milt, sperm motility percentage, the duration of forward motility, sperm concentration, milt production and milt pH were evaluated. On June 10, 2005, 72% of the males were spermiating, which increased to 100% in the middle of June and dropped to 72% by late June. Sperm motility percentage showed a significant improvement after beginning of spermiation (P < 0.001). Sperm concentration changed significantly (P < 0.001) in milt collected during sampling period. Duration of sperm motility increased significantly (P < 0.001) from beginning (8.22 min) through end (37.33 min) of spermiation. Milt production was maximal on June 15th, decreasing from a mean value of 3.12–0.46 × 109/ml. The high pH in milt was observed during the week of spermiation (P < 0.001).In conclusion, the results show that season has a significant influence on semen quality in male M. mastecembulus corresponding to spawning season in hot arid. Milt of good quality was especially collected in the middle of June. Spawning season in this fish species was found to be short.

The aim of this study was to determine the spermatological characteristics in male L. abu during the spawning season. Semen was collected weekly by abdominal massage from 26 males in March. In collected semen, volume, motility, duration of motility, concentration and pH were determined. In the L. abu sperm, volume (μl), motility (%), duration of motility (s), concentration (×109/ml), and pH values were found 45.76 ± 3.55, 54.25 ± 2.93, 330.15 ± 37.92, 4.27 ± 0.40 and 7.87 ± 0.05, respectively. A correlation was found between semen volume and semen pH. Semen volume and the duration of sperm motility were higher in the 2nd and 3rd sampling dates than in the 1st and 4th sampling dates (P < 0.05; P < 0.01, respectively). Neither sperm motility nor sperm concentration was affected by sampling dates. Major changes in semen pH were observed in the 4th sampling date (P < 0.001). The Pearson correlation test presented significant relationships with the duration of motility, semen volume, and motility. Semen pH values were significantly correlated with the sperm concentration and semen volume. Sperm concentration was inversely correlated with semen volume. Sperm motility and duration significantly correlated with total weight. Total length significantly correlated with the duration of motility and total weight. In conclusion, these characteristics represent a valuable baseline dataset for establishing a semen quality standard and provide background information that may be useful for assisted breeding programs in this species.