Black otocinclus

Hisonotus notatus

Also known as Notatus oto

FreshwaterFish

Care at a glance

Temperature: 72–81°F (22–27°C)
pH: 6.0–7.5
Adult size: 2 in (5 cm)
Minimum tank: 14 gal (54 L)
Temperament: Peaceful
Social behavior: Social
Swim level: Bottom
Difficulty: Medium
Breeding: Medium
Rarity: Rare
Origin: Coastal drainages, southeastern Brazil
Family: Loricariidae

Overview

The black otocinclus is a dusky little algae grazer that must be kept in a group; six or more settle far better than a lone fish, which tends to pine and waste away. The group spends the day working biofilm and soft algae off plants, wood and glass. It is gentle and easily startled, so keep it only with peaceful, small community fish in a calm, established tank. Its food is the film that grows on surfaces, supplemented with blanched vegetables and gentle prepared grazing foods once the fish are settled. A mature, planted tank of about 54 liters holds a starter group comfortably.

In the wild

This dusky catfish is native to coastal streams of southeastern Brazil, in drainages near Rio de Janeiro that run down to the sea. It grazes stems and stones in clear, gently moving water. A planted tank with fine substrate, driftwood and shady cover recreates this, and it depends on a mature tank with a good surface film. Keep the water soft to neutral, roughly pH 6.0 to 7.5, and mild to warm at about 22 to 27 C, changing water often to keep it clean.

Good to know

Hisonotus notatus is a small member of Loricariidae, about 5 centimeters long. It belongs to the same subfamily as the familiar shop otos but wears a darker, dusky coat. Like its relatives it is delicate on import and needs a settled tank rather than a new one. It has been raised in aquaria with some effort, laying small clutches of eggs on plant leaves and hard surfaces.

Did you know

Its home creeks drain the hills right behind Rio de Janeiro, so this quiet algae grazer lives almost within sight of some of the most famous beaches in the world.