several red bellied piranha day

Are Piranhas Nocturnal Or Diurnal?

While a fascinating fish, many people are interested in when Piranha are active. If you plan an aquarium, when exactly will you see your Piranha swimming, foraging and feeding.

So, are Piranhas nocturnal or diurnal? Piranhas are diurnal. That is they are more active during the day. Smaller Piranha feed throughout the day, but larger Piranha will feed nearer dawn and dusk if they can. Throughout the day Piranha can scavenge and forage for food.

What Do We Mean By Nocturnal And Diurnal With Piranha

The phrase nocturnal and diurnal is the scientific way of describing animals (or plants) preference for whether they are active during daylight hours or night time, with a lack of sunlight.

Owls are considered nocturnal, but humans, cows and gorillas are diurnal.

Piranha are diurnal, that is they are more active during the daylight. Like any animal, it doesn’t necessarily mean they are inactive or incapable during a lack of sunlight, just that they have a tendency towards daytime movement and feeding.

several red bellied piranha day

What Do Piranha Do In The Day

The word Piranha does not refer to specific species, and what they do during the day can vary depending upon where they are in the life cycle.

With respect to Red-Bellied Piranha, fish under 3 inches will spend the day searching for food. They are in a growth phase where food consumption is paramount. Piranhas grow quickly for the first 8 months or so.

Red-Bellied Piranha will also school amongst the foliage both waiting for prey and remaining in cover, avoiding becoming prey themselves. Depending upon the conditions they may also scavenge and forage for food.

It’s said that the larger the fish, or the more adult it is, the more likely it is to feed at dawn and dusk.

a red bellied piranha day

What Do Piranha Do At Night

While the black Piranha is said to be more active at night than other species of Piranha, this could be because it prefers low light conditions. Black Piranha live amongst the darker waters of the floodplains and wetlands of the Amazon, rather than the cleaner flowing rivers.

That said, most fish species are less active at night and take the opportunity to rest or ‘sleep’ in cover.

In an aquarium, you can help by really lowering the light levels so they do not get confused. The question of whether Piranha are diurnal or nocturnal sometimes gets confused because people keep the aquarium lights too bright.

So at night, it’s a good idea to really lower the lights to a moonlight type haze so the Piranha start to respond to daytime and nighttime behavior. Make sure the tank is out of streetlights direct light.

a red bellied piranha at night


So, as a preference Piranha in the wild will respond to the situation and conditions around them. During the night there’s a lot less light, and no artificial light so Piranha respond by being less active.

During the day, they will both scavenge for food, and hide amongst the foliage, trying to avoid being prey.

Some people think they are nocturnal because they prefer low light, like the Piranha, but this is not what nocturnal means, they are much more active during the day,

In an aquarium it can get a little confusing as aquarium light can confuse daylight hours. If the lights are too bright, with little cover, to a Piranha it looks like continual daylight. Male sure your home aquarium has a daytime and nighttime routine when the Piranha can respond properly.

That said, each Piranha can have personalities so there is no accounting for actual fish, but in general you will see more activity from Piranha during daylight, and this when you should feed them is possible.


Leave a Reply

Your email address will not be published. Required fields are marked *