How long do dolphin sleep?

The answer depends on the species of dolphin.

- Bottlenose dolphins: Typically sleep for 8 to 10 hours a day, but can sleep for as long as 18 hours.

- Common dolphins: Sleep for about 10 hours a day, but can sleep for as long as 14 hours.

- Risso's dolphins: Sleep for about 6 to 8 hours a day, but can sleep for as long as 10 hours.

- Humpback dolphins: Sleep for about 4 to 6 hours a day, but can sleep for as long as 8 hours.

- Amazon river dolphins: Sleep for about 3 to 4 hours a day.