Rainbow gudgeon

Sarcocheilichthys nigripinnis

Also known as Chinese rainbow gudgeon

FreshwaterFish

Rainbow gudgeon (Sarcocheilichthys nigripinnis) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 57–75°F (14–24°C)
pH: 6.5–7.8
Adult size: 6.3 in (16 cm)
Minimum tank: 53 gal (200 L)
Temperament: Mostly peaceful
Social behavior: Schooling
Swim level: Bottom
Difficulty: Medium
Breeding: No record
Rarity: Rare
Origin: Yangtze and coastal drainages, China
Family: Gobionidae

Overview

This is a coldwater gudgeon that is sociable and mostly peaceful, so keep a group of six or more near the bottom of a large, unheated tank. It is a busy forager that works gravel and open sand for food, and it colours up best when kept cool with good flow and clean water. It grows to a fair size for a gudgeon, so give it floor space and calm, similarly sized tankmates rather than tiny or nippy fish. Feed sinking foods: pellets, wafers, and frozen bloodworm, daphnia, and chopped prawn. Allow at least 200 litres so a group has room to move.

In the wild

It lives in cool rivers across much of China, from the Yangtze system to coastal drainages, working gravel runs and slower gravelly margins. Keep it in an unheated or cool tank of about 14 to 24 degrees Celsius with a neutral pH of 6.5 to 7.8. A bottom of gravel and sand, smooth stones, and moderate current suit it, and the cooler end of the range brings out its breeding colours.

Good to know

A gudgeon of the family Gobionidae, it reaches about 16 cm and turns rose, pewter, and near-black through the breeding season, the source of its rainbow name. Its species name nigripinnis means black-finned. In the wild females use a long ovipositor to lay eggs inside the gill cavity of living freshwater mussels, much as bitterlings do, though the species is not reliably bred in aquaria.

Did you know

It borrows a nursery from a mollusc. Females place their eggs inside the mantle cavity of a living freshwater mussel through a long ovipositor, so the young develop in safety behind the shell before swimming out, the same trick used by the unrelated bitterlings.

Tank mates

Rainbow gudgeon is a mostly peaceful, schooling species that keeps to the bottom. These picks match on water type, temperature, pH, size and temperament.