Male killer whales tend to weigh over 6 tons (12,000 lbs.) Female killer whales tend to weigh 3-4 tons (6,000-8,000 lbs.) Orcas can weigh up to 5 tons to 7 tons males can weigh from 10-11 tons and females can weigh from 7-8 tons. read more
The blue whales heart alone can weigh as much if not more than a fully grown dwarf sperm whale. In fact some of the largest blue whales have had hearts that weigh as much as 2,500 lbs., which is equivalent to the weight of a small car. read more