Goblin sundadanio

Sundadanio goblinus

Also known as Goblin blue sundadanio, Neon blue rasbora

FreshwaterFish

Goblin sundadanio (Sundadanio goblinus) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 73–81°F (23–27°C)
pH: 4.5–6.5
Adult size: 0.9 in (2.3 cm)
Minimum tank: 11 gal (40 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Difficult
Breeding: Hard
Rarity: Rare
Origin: Peat swamps of eastern Sumatra, Indonesia
Family: Danionidae

Overview

A blackwater nano fish for experienced keepers, best in a school of a dozen or more with only the smallest, gentlest company such as chili rasboras and nothing likely to outcompete or eat it. It is peaceful and stays in midwater, showing its blue and green best under dim light over dark botanicals. Feed micro live and frozen foods, such as baby brine shrimp, microworm, cyclops, and daphnia, along with fine dry foods. The real work is water chemistry: a mature, soft, acidic blackwater tank of around 40 liters, held stable.

In the wild

The goblin sundadanio comes from coastal peat swamp forests in eastern Sumatra, where the water is dark, soft, and strongly acidic. It needs a mature blackwater tank with peat, leaf litter, and botanicals, dim lighting, gentle flow, and very stable conditions. It wants warm, acidic water, 23 to 27 degrees Celsius with a pH of 4.5 to 6.5, ideally below 6.0.

Good to know

Sundadanio goblinus is a miniature member of the danio family, Danionidae, staying under about 2.5 centimeters. Kottelat named it in the 2011 review that split the old axelrodi into a genus of many species; goblinus refers to its small size and slightly gnarled look. Males can produce sound, and captive breeding is difficult, so it rates as a hard spawner.

Did you know

Male Sundadanio can croak, using modified muscles and bones around the swim bladder, so a displaying group of these tiny fish quietly growls and clicks to itself down in the leaf litter.