African moony

1) Where they come from

African moonies (Monodactylus sebae) come from West African coastal areas—think river mouths, mangroves, and lagoons where fresh and salt water mix. That “in-between” habitat is why they’re so at home in brackish tanks, and why they often look stressed in straight freshwater long-term.

2) Setting up their tank

Give them space first, décor second. Moonies are tall-bodied, fast, and they school—so they need open swimming room more than a bunch of hardscape. In a cramped tank they get skittish, banged-up noses, and that “spooked pinball” behavior.

• Tank size: I’d start at 55g/200L for a small group, and bigger is honestly better as they grow (they’re not tiny fish).
• Group size: 5–7+ if you can. They act way calmer in a real group.
• Filtration: strong and steady. They’re active eaters and you’ll appreciate extra bio capacity.
• Flow: moderate. They don’t mind current, and it keeps them cruising.
• Scape: open center, plants/wood/rock pushed to the sides so they can loop around.

For brackish, use marine salt mix (not “aquarium salt”). Aim for low-to-mid brackish for most setups and adjust slowly over time—especially if your fish are newly purchased and coming from lower salinity.

3) What to feed them

Moonies eat like little piranhas with manners—quick, enthusiastic, and always ready. Mine did best on a varied diet with a solid staple pellet and lots of “extras” rotated in so they don’t get skinny or picky.

• Staple: quality omnivore pellets/flakes (they take to pellets fast).
• Frozen: mysis, brine shrimp, chopped prawn, krill (go easy—rich), bloodworms as an occasional treat.
• Greens: spirulina flakes, blanched spinach/zucchini, or algae-based wafers they can graze.
• Feeding rhythm: smaller meals 1–2x/day beats one huge dump (they’ll inhale it either way).

4) Behavior and tankmates

They’re peaceful, but they’re busy. A confident school will glide around like shiny kites; a nervous pair will hide, dart, and scrape themselves up. The whole vibe improves when you keep them in a proper group and don’t crowd them with bullies.

• Temperament: generally peaceful schooling fish, can be “bossy” at food time.
• Best with: other brackish community fish that can handle similar salinity and aren’t delicate.
• Avoid: tiny fish (they may not try to eat them, but stress and feeding competition is rough), fin-nippers, and overly aggressive predators.

5) Breeding tips (real talk)

Breeding African moonies in the home aquarium is rare. They’re schooling fish that likely spawn in specific seasonal/brackish-to-marine conditions, and sexing them is not straightforward. I’ve kept groups for a long time and never saw anything close to a dependable spawn.

6) Common problems to watch for

Most “moony problems” come from three things: wrong salinity (or sloppy changes), too small a tank/group, and beat-up fins from stress or tankmates. Fix the environment and they usually bounce back fast.

• Ich/white spot: can show up after new purchases or sudden swings. Quarantine new fish if you can.
• Fin damage: from nippers, décor they crash into, or frantic schooling in tight tanks.
• Skin irritation/flashing: often from unstable salinity, poor water quality, or adding dry salt to the tank.
• Food frenzy injuries: they can smack into glass/hardscape when competing—another reason for open swimming space.
• Slow decline in freshwater: they may “survive” but look washed out, get more disease, and act jumpy.