Smallscale hemiodus

Hemiodus microlepis

Also known as Silver hemiodus microlepis

FreshwaterFish

Smallscale hemiodus (Hemiodus microlepis) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 75–84°F (24–29°C)
pH: 5.5–7.0
Adult size: 11 in (28 cm)
Minimum tank: 159 gal (600 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Difficult
Breeding: No record
Rarity: Rare
Origin: Amazon and Orinoco basins
Family: Hemiodontidae

Overview

The smallscale hemiodus is a big, restless schooling characin. It only settles in a crowd, so keep at least six together; on its own it stays skittish and dashes about. It patrols the open middle water at speed, so it needs a long tank with plenty of clear swimming room and gentle current, sharing space with other calm, good-sized fish rather than tiny tankmates. It grazes and micro-feeds by day, so offer sinking foods, frozen items, and some vegetable matter. A group this size needs a large tank of about 600 liters or more.

In the wild

The smallscale hemiodus ranges through open water in the Amazon and Orinoco basins, moving in shoals along sandy river reaches. Give it a long tank with a sandy bottom, brisk flow, and high oxygen. Hold it in soft, warm water of about 24 to 29 C at a pH of 5.5 to 7.0. It uses the whole length of the tank, so leave the swimming lanes open rather than filling them with hardscape.

Good to know

Hemiodus microlepis belongs to Hemiodontidae, the halftooths, and reaches about 28 centimeters. Its species name means small-scaled, for the fine scaling that gives it a smooth silver sheen. The family name points to its teeth: members carry teeth only in the upper jaw, the lower jaw being toothless, so the fish grazes with the top half of its mouth. Breeding is not recorded in aquaria.

Did you know

Hemiodus means halftooth. These fish keep teeth only in the upper jaw and none in the lower, so they scrape and graze using just the top half of the mouth, an odd setup that ended up naming the whole family.

Tank mates

Smallscale hemiodus is a peaceful, schooling species that keeps to the middle. These picks match on water type, temperature, pH, size and temperament.