Celebes rainbow

Marosatherina ladigesi

FreshwaterBrackishFish

Care at a glance

Temperature: 72–82°F (22–28°C)
pH: 7.0–8.0
Adult size: 3.1 in (8 cm)
Minimum tank: 25 gal (95 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Difficult
Breeding: Hard
Rarity: Rare
Origin: Sulawesi
Family: Telmatherinidae

Overview

Celebes rainbows are delicate, slender fish that settle best in a group of eight or more, where males spread their fins and display to one another. They swim in the middle of the tank and stay peaceful, but they are easily bullied, so choose equally gentle tankmates and avoid boisterous or fin-nipping company. They like clean, well-oxygenated water with a little movement and can be sensitive to poor conditions, which makes them more demanding than the average community fish. Feed small foods such as fine flake, frozen cyclops, daphnia, and baby brine shrimp. Aim for a tank around 95 liters or larger.

In the wild

This species is endemic to southern Sulawesi in Indonesia, where it lives in clear, flowing streams and spring-fed pools around the Maros karst, some of them close to the coast with a touch of salt. The water is warm, hard, and alkaline, matching a pH of about 7 to 8 and a temperature between 22 and 28 degrees Celsius. A slightly brackish setup suits it, so recreate the habitat with fine sand, smooth rock, some plants, and gentle current from strong, clean filtration.

Good to know

Despite the rainbow in its name, the Celebes rainbow is not a true rainbowfish. It belongs to Telmatherinidae, the sailfin silversides, a family centered on Sulawesi and only distantly related to the Melanotaeniidae of Australia and New Guinea. It reaches about 8 centimeters, with males showing longer dorsal and anal fin extensions than females. It scatters eggs among fine plants over an extended spawning period, attaching them by fine threads, and the small, slow-growing fry make breeding difficult.

Did you know

The genus name Marosatherina points to Maros, the region of Sulawesi where the fish is found, paired with a word for silverside. The species name honors the German aquarium scientist Werner Ladiges.