The reindeer is the only mammal that can see UV light.
17
Urechis unicinctus is a species of marine spoon worm that is widely referred to as the ‘penis fish’.
2
The sound of a tiger's roar can travel a distance of up to 2 miles (~3 km).
255
A koi fish, named "Hanako", was owned by several individuals over many years and lived to be 226 years old, dying in 1977.
6
The octopus does not have a blind spot.
273
Nervous dogs wag their tails to the left, and happy dogs to the right (from the dog’s point of view) – and fellow canines pick up on this lop-sided tail language.
10
Sheep, goats, octopuses, and toads have rectangular pupils.
7