Endler's livebearer

Where they come from (and why it matters)

Endler’s livebearers come from a handful of lagoons and streams in Venezuela. In the wild they’re often in warm, plant-choked water with lots of algae and tiny critters to pick at.

That background explains why they’re so happy in a well-planted tank and why they’re constantly grazing. If you give them cover and steady warmth, they act like little fearless birds.

Setting up their tank

You don’t need a huge tank to enjoy Endlers, but you do want stability. I’ve had the best luck starting them in a cycled 10–20 gallon, heavily planted, with gentle flow.

• Tank size: 10 gallons works for a small group; 20 long is even nicer for males showing off and chasing
• Temp: ~74–80°F (23–27°C). I keep mine around 76–78°F
• pH/hardness: They handle a range, but they’re typically happier in neutral to slightly alkaline water with some hardness
• Filtration: Sponge filter or a baffled HOB—these fish don’t love getting blasted around
• Plants: Guppy grass, hornwort, java moss, floating plants (their fry will thank you)

Cover matters more than you’d think. Even if you’re not trying to breed them, they relax and color up better with plant thickets and little shaded areas.

What to feed them

Endlers eat like tiny pigs, but their mouths are small. Think “small foods, often,” and they’ll stay round and colorful without bloating.

• Daily staple: quality micro pellets or finely crushed flake
• Color/conditioning: baby brine shrimp, daphnia, cyclops, or frozen foods chopped small
• Greens: spirulina flakes, blanched zucchini slivers, or letting the tank grow a bit of biofilm/algae for them to pick at

Behavior and tankmates

Males are nonstop little showboats. They spar, flash their tails, and chase each other around—but it’s usually more drama than damage.

They’re peaceful with basically anything that won’t eat them. The main “problem” is that they’re small and curious, so big or nippy fish can stress them out fast.

• Great tankmates: small tetras (ember/neon-sized), rasboras, corydoras, otos, kuhli loaches, snails, shrimp (adults usually fine)
• Use caution: bettas (some ignore them, some hunt them), barbs, larger gouramis, anything known for fin nipping
• Avoid: cichlids, larger predatory fish, and anything that sees “tiny livebearer” as a snack

Breeding tips (because… they will)

If you keep males and females together, you’re basically agreeing to raise fry. Females can store sperm and drop multiple batches over time, even if you separate them later.

• Ratio that keeps stress down: 1 male to 2–3 females (males are relentless)
• Fry survival trick: dense plants (guppy grass/java moss) and floating cover
• If you want more fry: feed small live/frozen foods and keep the tank stable and warm
• If you want fewer fry: run a male-only tank, or keep them with fish that will snack on newborns (without terrorizing the adults)

Common problems to watch for

Most Endler issues come down to two things: sloppy water from overfeeding, or weak stock from heavy inbreeding. Start with healthy fish from a good source and you dodge a lot of headaches.

• Shimmying (wobbling in place): often shows up in soft/unstable water or stressed fish—harder water and steady temps usually help
• Stringy white poop: can be stress or internal parasites; try improving diet and observing before medicating the whole tank
• Clamped fins/hiding: usually water quality, temperature swings, or bullying
• Fungus/fin rot: commonly follows stress or dirty water—clean up the tank and address the cause instead of just chasing meds
• Sudden losses in a new tank: ammonia/nitrite spikes; Endlers don’t forgive “uncycled” setups