Red Neon Blue-eye (Luminatus Blue-eye)

1) Where they come from

Red Neon Blue-eyes (Pseudomugil luminatus) come from New Guinea, where they hang out in warm, plant-choked creeks and swampy edges with gentle flow and tea-stained water. That “soft, leafy, calm” vibe explains a lot about what they like in the aquarium.

2) Setting up their tank

Think of these as small, active, mid-to-top swimmers that hate being in the open with nowhere to duck into. A planted tank with broken sight lines is your best friend—fine-leaved plants, stem plants, and some floating cover.

Tank size-wise, you can keep a group in a 10 gallon, but they look and act way better in a 15–20 long where they can zip around. They’re not huge, but they use the space.

• Group size: 8–12+ is where they start acting confident (more is better)
• Filtration: gentle to moderate flow; sponge filters or a baffled HOB work great
• Aquascape: lots of plants + a bit of open swimming lane in front
• Lighting: moderate; floating plants help them relax and bring out color
• Lid: yes—these little rockets can jump, especially during chasing/spawning

Water temp in the mid-70s°F (around 24–26°C) has been a sweet spot for me: good activity, good appetite, and fewer random losses than running them too cool. Keep the tank clean, but don’t blast them with current like they’re danios.

3) What to feed them

They’ve got tiny mouths and they’re picky about particle size. If you feed like you would for tetras, half the food just drifts past them. Small foods, frequent small meals—that’s the game.

• Staples: quality micro-pellets or very fine flakes (crush it between your fingers)
• Frozen: baby brine shrimp, cyclops, daphnia—anything small
• Live (if you can): baby brine shrimp is basically a cheat code for color and breeding
• Feeding rhythm: 1–2 small feedings a day; skip a day now and then if your tank runs rich

4) Behavior + tankmates

They’re peaceful, curious, and kind of “busy” all day. Males will posture and do little chasey dances—usually harmless, and honestly one of the reasons to keep them. In a cramped tank or with too few fish, that chasing gets annoying fast.

• Best tankmates: small rasboras, ember tetras, chili rasboras, otocinclus, small Corydoras, peaceful shrimp (adult shrimp usually okay)
• Use caution with: fast fin-nippers (some barbs), bigger gouramis, anything that makes them hide all day
• Avoid: larger fish that see them as snacks, or aggressive livebearers that never stop pestering them

5) Breeding tips (they’re fun to breed)

They’re classic egg scatterers and will spawn pretty often once comfortable. Males display, females dip into fine plants or spawning mops, and you’ll get a few eggs at a time rather than one big dump.

• Setup: a clump of java moss, guppy grass, or a yarn spawning mop
• Ratio: 1 male to 2–3 females keeps the pressure off any single female
• Egg collection: pull the mop/moss every day or two and move it to a small hatch container
• Hatching: usually around 1–2 weeks depending on temperature
• First foods: infusoria/micro foods early, then baby brine shrimp as soon as they can take it

6) Common problems to watch for

Most issues I’ve seen come from three things: stress from a bare/bright tank, being kept in too small of a group, and trouble getting them eating well early on. They’re not fragile, but they’re not “bulletproof community fish” either.

• Washed-out color and hiding: usually too little cover, too much light, or pushy tankmates
• Fin wear or torn fins: often male chasing in a small group/tight tank; add more fish/space/cover
• Not eating: offer smaller foods; try frozen/live; watch for outcompeting tankmates
• Sudden losses after purchase: acclimation stress + young fish; keep water stable and don’t blast them with high flow
• Ich/velvet risk: they show stress quickly—quarantine new fish if you can

If you give them plants, a decent-sized group, and small foods they can actually grab, they’ll reward you with nonstop activity and those ridiculous red-and-blue flashes every time the males decide to show off.