Kubuna hardyhead

Craterocephalus randi

Also known as Australian hardy head, Rand's hardyhead

FreshwaterFish

Care at a glance

Temperature: 72–82°F (22–28°C)
pH: 6.8–7.8
Adult size: 3.1 in (8 cm)
Minimum tank: 30 gal (112 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Medium
Breeding: Medium
Rarity: Rare
Origin: Southern New Guinea rivers
Family: Atherinidae

Overview

This is an active, peaceful shoaling silverside, so keep it in a group of six or more and give it open midwater to cruise. Single fish or tiny groups turn nervous and fade, while a proper shoal stays out and busy. It swims mainly in the middle of the tank and picks small foods from the water and off plants, so offer flake, micro pellets, and small frozen items such as daphnia and mosquito larvae. It mixes well with other calm, similarly sized community fish like rainbowfish, gobies, and glassfish. A tank of around 112 liters or larger, with steady flow and room to swim, suits a starter group.

In the wild

The Kubuna hardyhead comes from clear rivers, streams, and lakes across southern New Guinea, over beds of sand, mud, and rock. Recreate that with a soft sand base, some driftwood and plants, and a gentle current from a filter return or small powerhead for oxygen. Keep the water clean and well filtered at 22 to 28 C and pH 6.8 to 7.8, with regular partial water changes, since this genus is sensitive to poor water quality.

Good to know

Craterocephalus randi belongs to Atherinidae, the hardyheads and silversides, a group closely tied to the rainbowfishes and marked by two separate dorsal fins. It is a slim, pewter-toned midwater fish that reaches about 8 centimeters. Breeding is moderately challenging: like its relatives it is an egg scatterer that attaches small eggs to fine plants and trailing roots over a long spawning period.

Did you know

Although it looks plain beside its rainbowfish cousins, the two separate dorsal fins give the family away. That twin-fin silverside feature places the hardyheads right next to the rainbowfishes on the family tree.