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Knaack's cory

Hoplisoma knaacki

Also known as Corydoras knaacki

FreshwaterFish

Care at a glance

Temperature
73–81°F (23–27°C)
pH
5.8–7.2
Adult size
1.8 in (4.5 cm)
Minimum tank
16 gal (60 L)
Temperament
Peaceful
Social behavior
Shoaling
Swim level
Bottom
Difficulty
Medium
Breeding
Medium
Rarity
Rare
Origin
Rio Madre de Dios basin, southeastern Peru
Family
Callichthyidae

Overview

A 60-liter sand-bottom tank holds a happy shoal of six. It eats prepared sinking foods immediately and breeds along standard cory lines with cool water changes, with several hobby reports to draw on. A good companion for pencilfish and small Peruvian tetras.

In the wild

Knaack's cory lives in sandy lowland streams of Peru's Madre de Dios drainage, often alongside Fuller's cory. It wants the same setup: fine sand, wood, leaves, and clean flowing water at 23 to 27 degrees Celsius with pH 5.8 to 7.2.

Good to know

Described in 2016 by Tencatt and Evers and named for the Bolivian-cory specialist Joachim Knaack, this species reaches about 4.5 centimeters and is listed as Hoplisoma knaacki in the 2024 revision. It is one of the round-snouted spotted corys of the Madre de Dios that hobby lists once lumped under catch-all names.

Did you know

Two corys from the same Peruvian rivers honor a doctor and his craft: knaacki is named for the describer of Bolivian corys, and it swims beside fulleri, named for the man who codes the unnamed ones.

Tank mates

Knaack's cory is a peaceful, shoaling species that keeps to the bottom. These picks match on water type, temperature, pH, size and temperament.

Check the full mix in the stocking calculator

Common questions

What size tank does a Knaack's cory need?

A Knaack's cory needs at least 16 gal (60 L). It spends most of its time in the bottom.

What temperature and pH do Knaack's cory need?

Knaack's cory are comfortable at 73–81°F (23–27°C) with a pH of 5.8–7.2.

How big do Knaack's cory get?

An adult Knaack's cory reaches about 1.8 in (4.5 cm).

Do Knaack's cory need a group?

Yes. Knaack's cory are a shoaling species and should be kept in a group, not singly.

Where to buy

Some links may not be the exact species or variety.

…or ask your local fish store.

Appears in

Freshwater fish · Corydoras · Schooling fish · Community fish · Bottom dwellers

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