Why Do My Corydoras Keep Hiding? {Top 6 Reasons}

Corydoras are peaceful and easy to keep in an aquarium. But, why do my corydoras keep hiding?

I always thought these cory catfish enjoy swimming just above the substrate. This species of fish are shy, but are my hiding corydoras sick or stressed?

This article intended to give you all the reasons why corydoras keep hiding.

Why Do My Corydoras Keep Hiding?

When Corydoras are new to a tank, they tend to hide until they feel comfortable. In community tanks, Corydoras might keep hiding if they are

  1. stressed
  2. bullied
  3. overcrowded 
  4. in poor water quality
  5. too hot/cold
  6. smaller than other tankmates

Corydoras are peaceful and easy to keep in an aquarium. Corydoras are naturally shy, and they spend most of their day at the tank base, mostly hiding. Corydoras take cover under plants and other substrates.

Corydoras Keep Hiding

Why are Corydoras Shy?

Corydoras are generally shy and timid. They spend most of their day at the base of the tank, either resting or hiding. However, you will find them shoaling during the evening and night.

If you find Corydoras at the top of the tank, they are either in search of oxygen or food. They don’t mix with other fish in community tanks. They prefer to keep to themselves.

This species of aquarium fish are completely peaceful. They don’t attack other members of the tank or pose any threat whatsoever.

Corydoras will live comfortably with peaceful members in the same tank without interfering in their activities. However, they will hide once they feel threatened.

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Are Corydoras Peaceful?

Yes. The trademark appearance of Corydoras is its small body. They have obvious features that make them different from members of other species.

They can only grow up to 2.5 to 4 inches, even when all conditions are favorable. The smallest ones can be around just one inch long. Corydoras have three pairs of barbels on their face. These barbels are sensitive, and they are useful in detecting food within the sand.

Their eyes are quite wide, which is an adaptive feature aside from making them adorable. These wide eyes keep them aware of their environment.

Corydora Camouflage

Corydoras primarily have three color categories. They can have thick colors that allow them to blend with the bed of the river. Others can be pale and shimmering.

This fish species has a flat underside and short face. They look armored because their pectoral fin sticks out of their body. Members of Corydoras have two types of dorsal fins. Some have their dorsal fins facing up like sail while others have rounded fins. The tail fins are forked, and it adds considerably to their length.

Corydoras can tap oxygen with their intestinal lining. This behavior is an adaptive response in water with low oxygen content. However, they occasionally do it even under good conditions.


Corydoras are adorable aquarium fish that will fit into almost any tank. They are easy to keep in community tanks. They also exhibit some behaviors that can communicate how they feel.

Corydoras spend most of their day at the tank’s base, taking cover under live plants or other decorations. They will keep hiding if they are uncomfortable in the tank, or they feel threatened.


Hello, I'm Jason. I'm the guy behind HelpUsFish.com. I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.