do the fish open it's eyes when it is sleeping?
By chuanyan82
@chuanyan82 (64)
China
2 responses
@PLATOANDPIG (46)
• China
20 Aug 07
The animals live on the land have eyelids to keep their eyes wet.Since fish lives in water , it doesn't need eyelids and of course they never close their eyes.
@oscarbartoni (2581)
• United States
10 Dec 07
There are certain fish like some catfish that help to swallow their food by "blinking" or bringing their eyes down into their bodies to help in getting their food into their stomach and also some catfish come up to the surface to breath in air, they will swallow air (using their eyes to help) and the air will go into the intestines to extract the oxygen.
@ryanphil01 (4182)
• Philippines
27 Jul 07
Fish don't exactly sleep the same way you or I sleep. Rather, many fish exhibit resting behaviour where they are in an inactive state for part of the day. For example, in a coral reef area there are some fish which are active during the day and rest in crevices or caves at night, while other fish are active at night and rest during the day. When these fish are inactive, they are usually resting quietly on the bottom and are hopefully out of the sight of any predators. Some fish, like tuna, must constantly swim to keep water moving over their gills, and are therefore active at all times (although they might be less active and swim slower during the night). Their EYES STAY OPEN because fish DON'T HAVE EYELIDS. Some sharks have nictitating membranes, which cover their eyes but are believed to function more for protection of the eye than to stop light from coming in.
Source: http://oceanlink.island.net/ask/fishy.html
