Four-spot headstander

Pseudanos varii

Also known as Vari's headstander

FreshwaterFish

Care at a glance

Temperature: 72–81°F (22–27°C)
pH: 5.5–7.5
Adult size: 8.3 in (21 cm)
Minimum tank: 79 gal (300 L)
Temperament: Mostly peaceful
Social behavior: Shoaling
Tankmates: Tankmates with caution
Swim level: Middle
Difficulty: Medium
Breeding: No record
Rarity: Rare
Origin: Rio Negro basin and upper Orinoco
Family: Anostomidae

Overview

The four-spot headstander is a peaceful, shoaling fish that should be kept in a group of six or more, since lone fish become withdrawn and stressed. It holds the family tilted, head-down posture in the middle and lower water, grazing biofilm and aufwuchs from wood and rock. It is gentle but easily crowded out at feeding, so keep it with calm tankmates and treat boisterous or nippy species with caution. Feed sinking pellets, algae wafers, and small frozen foods with some vegetable matter, and provide plenty of driftwood to browse. It reaches about 21 centimeters, so allow a tank of around 300 liters or more for a group, with a tight lid.

In the wild

This species lives in soft, warm blackwaters shared between the Rio Negro basin and the upper Orinoco, which connect through the Casiquiare, grazing among sunken branches in seasonally flooded forest. Recreate that with a dim, tannin-stained tank: soft sand, dense driftwood, leaf litter, gentle flow, and clean water kept warm at about 22 to 27 C and soft and acidic to neutral, roughly pH 5.5 to 7.5.

Good to know

A toothed headstander in the family Anostomidae, it was described in 2012 and grows to about 21 centimeters. Its name honors Richard Vari, a specialist in characiform fishes at the Smithsonian who studied the anostomids in depth. Aquarium breeding is not recorded.

Did you know

The fish is named for Richard Vari, one of the leading scientists on its own family, so the four-spot headstander effectively carries a permanent scientific dedication swimming around in its name.