Abstract
The present study was conducted to examine the ejaculate characteristics and liquid storage of common bottlenose dolphin semen. Semen samples were collected from five males, and were evaluated for pH, ejaculate volume, sperm concentration, total spermatozoa, motility, viability, and morphological abnormalities. The quality of semen in liquid storage was assessed by using Biladyl, EYC, or BF5F, and the semen was monitored daily for sperm motility and viability. With the exception of volume, none of the above characteristics were significantly different among the semen fractions. However, there was a negative correlation (r=-0.539, p<0.01) between the sperm concentration and the viability. Males in full maturity and males with higher fertility frequency (higher social status) at the same institution had higher sperm concentrations and lower sperm viability. The sperm characteristics did not show any seasonal variations. The sperm motilities in semen diluted by EYC or BF5F were significantly preserved for two days (p<0.05). The viabilities were at a high level for seven days in all treated semen samples. In addition, when the seminal plasma was eliminated from semen, the motility was significantly decreased from the day of the liquid storage (p<0.05). From these results, we concluded that 1) the viability could be influenced by maturity or male fertility frequency (social status); 2) the captive bottlenose dolphin’s semen can be collected in any season; 3) EYC and BF5F are available as extenders for the short-term storage of bottlenose dolphin spermatozoa; and 4) the seminal plasma has a beneficial effect on the liquid storage of the semen.
