– Species like dolphins do not sleep in a clearly recognisable way. They literally sleep with one eye open as they to do the breathing process consciously.
– Insects such as fruit flies as a small percentage of fruit flies sleep for an average of 72 minutes per day.
Animals that do not have central nervous system like jellyfish do not need to sleep or are incapable to sleep.
– Fish like Tilapia are known to stay awake and active for the first 22 weeks after birth.