Betta fish do sleep. All living creatures need to rest. Sleep is a must for survival. It is just that the sleeping habits differ in each. Sleeping habits differ in fish depending on whether they are diurnal or nocturnal. The marine fish which are nocturnal, sleep during the day and hunt at night. The tropical fish which are diurnal, stay very active during the day and sleep at night. In other words, they follow the same sleep cycle as the humans.
Fish sleep mostly when the lights go out. If they are resting during the day time, they would rest under the shade of the leaves of the plants in the tanks. When sleeping, most fish appear pale.They keep their eyes open wide. They don’t have eyelids and hence their eyes are always open. Bettas are tropical fresh water fish. They have the same sleeping cycle like us humans. They sleep when we sleep or sleep during the dark hours. That is the reason most of us would not have seen the bettas sleep and we wonder – do betta fish sleep?
It is necessary to switch off the light in the tank and create a dark atmosphere for the bettas to sleep. Some of you would have noticed the bettas startled and terrified when you switch on the lights suddenly. That is because the light would have woken them from their sleep. It is essential to switch off the lights for another reason too. Prolonged hours of lighting would heat up the water and the atmosphere, making it hard for the bettas to rest.