Sei Whales are the third largest rorqual, after the blue whale and the fin whale. They have a body length between 14 and 16 m (43 - 52 ft), and they weigh between 20 and 25 tonnes (20 - 24.5 tons).
Sei Whales are found in waters worldwide.
Sei Whales feed on small fish, squid and krill. They eat around 900 kgs (1,985 lbs) of food per day.
Sei Whales breed during the winter months and after a gestation of 10.5 - 12 months a single calf is born. The calf is weaned at 6 - 7 months old and they reach sexual maturity at around 10 years of age.