Abstract: Ultrasonographic monitoring of folliculogenesis and prediction of ovulation was used for ten years to control breeding in a group of Indo-Pacific bottlenose dolphins (Tursiops aduncus) at Ocean Park, Hong Kong, where male and female dolphins were housed separately from 1991. When folliculogenesis was identified in a selected female, the cycle was monitored until ovulation was predicted within the next 12 to 24 h; a male was selected and then placed with the female overnight.

Ultrasonography was repeated the next morning to determine ovulation. If ovulation had occurred, the animals were separated; if not, the pair remained together until ovulation was confirmed. Ultrasonography was subsequently used to monitor the development of the corpus luteum and to identify pregnancy. This procedure was conducted 11 times between 1993 and 2003.

In nine cases, ovulation was predicted accurately and occurred within 24 hours. In two cases, ovulation occurred within two to four days of the predicted date. In ten cases, pregnancy ensued. To date, nine calves have been born live after gestation lengths of 349-382 days.

Key Words: BOTTLENOSE DOLPHIN; TURSIOPS ADUNCUS; OVARIAN CYCLE; CONTROLLED BREEDING; ULTRASONOGRAPHY

Document Type: Research article

DOI: 10.1578/AM.31.1.2005.89

Page Numbers: 89 – 95