Sebae mono

Monodactylus sebae

Also known as African moony, Sebae moony, Striped fingerfish

BrackishSaltwaterFish

Sebae mono (Monodactylus sebae) — Ltshears · CC BY-SA 3.0

Care at a glance

Temperature: 75–82°F (24–28°C)
pH: 7.2–8.5
Adult size: 7.9 in (20 cm)
Minimum tank: 119 gal (450 L)
Temperament: Mostly peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Difficult
Breeding: Hard
Rarity: Common
Reef safe: Not reef safe
Origin: Coastal West Africa: estuaries and mangrove lagoons from the Canary Islands to Angola
Family: Monodactylidae

Overview

Keep them in a group of at least five or six, because a proper shoal is what keeps these nervous fish calm; singles and pairs hide, lose color, and squabble. A group of tall, active fish needs a big tank, on the order of 450 liters or more with real height and a long footprint. They cruise the middle and upper water column and are mostly peaceful, though bigger fish get bossy and will harass small or slow tankmates, so keep them with hardy brackish species like scats, silver scats, and archers. Hold the water hard and alkaline at a pH of 7.2 to 8.5 and 24 to 28 C, and step the salinity up slowly as they mature. Feed a varied omnivore diet with meaty frozen foods and a solid share of greens.

In the wild

Sebae monos come from the estuaries, lagoons, and mangrove-lined coasts of West Africa, from the Canary Islands down to Angola, living in tidal water that swings from nearly fresh to fully marine. Like the silver mono, the salt requirement rises with age: juveniles tolerate low brackish, but adults do best in high brackish to marine conditions, so build toward a system that can reach marine salinity. This is a very tall, diamond-shaped fish, so it needs height as well as length. Give it a large tank with alkaline hard water at a pH of 7.2 to 8.5, a temperature of 24 to 28 C, strong filtration, and plenty of open swimming room.

Good to know

This is a taller-bodied cousin of the silver mono in the family Monodactylidae, more disc-like and often measured by height rather than length. Bodies reach roughly 20 to 25 cm and can stand nearly as tall as they are long, marked with bold vertical bars through the eye and body. It is euryhaline and pelagic-spawning, so it is not bred in aquaria and stock is wild-collected as juveniles.

Did you know

Its dramatic tall shape is why hobbyists sometimes buy a single juvenile as a novelty, not realizing it wants a group and a tank that ends up closer to a reef system in salinity. A well-grown school of adults with their high, banded silver bodies is one of the more striking sights in the brackish hobby.