Dwarf thorny catfish

Physopyxis lyra

Also known as South American moth cat, Lyra catfish

FreshwaterFish

Care at a glance

Temperature: 73–82°F (23–28°C)
pH: 6.0–7.5
Adult size: 1.4 in (3.5 cm)
Minimum tank: 11 gal (40 L)
Temperament: Peaceful
Social behavior: Social
Swim level: Bottom
Difficulty: Medium
Breeding: No record
Rarity: Rare
Origin: Amazon basin leaf litter zones
Family: Doradidae

Overview

This is a tiny, cryptic armored catfish that lives its whole life in and around leaf litter, so build the tank around a deep bed of leaves and small wood. It is peaceful and sociable, best kept in a small group, and it should only share space with equally small, gentle fish, since anything larger will simply outcompete or eat it. Feed small sinking foods, micro pellets, and frozen items such as cyclops and baby brine shrimp, worked down among the leaves. A modest tank of around 40 liters is plenty for a group of these 3.5 cm fish.

In the wild

Physopyxis lyra lives in the Amazon and Essequibo basins, in warm, very shallow water among drifts of submerged leaves and waterlogged wood. For this fish leaf litter is not decoration but habitat, so provide a thick layer of botanicals over soft sand, subdued light, and calm, gently filtered water. Keep it warm at 23-28 C and soft and slightly acidic to neutral, about pH 6-7.5. Tannins leaching from the leaves suit it.

Good to know

At around 3.5 cm this is the smallest known member of the family Doradidae, yet it carries the full set of bony plates and hooked flank scutes found on its much larger relatives. The family ranges from this species all the way up to the metre-long ripsaw catfish, Oxydoras niger. Even at its miniature size it can make faint stridulation sounds. Its breeding is not documented in aquaria.

Did you know

It is the smallest of all the thorny catfishes, complete with full armor plating at a length of only about 3.5 cm, roughly the size of one of the fallen leaves it likes to hide beneath.