2006-07-05 09:09:15 · 4 answers · asked by Rescuediver 1 in Science & Mathematics ➔ Zoology
their eyelids are composed of a small transparent film. dolphins sleep with one eye open, and swim in a circular direction with the open eye on the outside, constantly looking for food. in the middle of their sleep, they reverse directions and close the other eye, opening the other.
2006-07-05 09:15:25 · answer #1 · answered by Anonymous · 3⤊ 2⤋
Yes, they sleep. In coral reefs some fish do an extraordinary thing: they produce a tenuous mucus that isolates them from the surrounding water, avoiding the danger of being smelled at distance by predators that are awake at nights, otherwise they'd be a fast and easy snack.
2006-07-05 11:11:23 · answer #2 · answered by pogonoforo 6 · 0⤊ 0⤋
My tropical fish "sleep" and are scared when woke up. They know when the light go out. Some catfish are more active at night search for food like owls.
2006-07-05 09:24:46 · answer #3 · answered by Some Guy 1 · 0⤊ 0⤋
As said above, they sleep, although dolphins and whales have the ability to turn off only half of their brain (ie, one half is always 'on') so they are constantly aware, and eventually get the sleep they need.
2006-07-05 12:53:34 · answer #4 · answered by Pak 1 · 0⤊ 0⤋