Endlers are easy to fall for. They are tiny, they shimmer, and they have a reputation as the gentler, more peaceful alternative to guppies. I kept them — a Japan Blue trio, one male and two females — and I genuinely liked these little fish. But "peaceful" turned out to be more complicated than the care sheets suggest, and my shrimp paid the price. This is the honest version: what is true about endlers, and what only shows up once you keep them yourself.
What's genuinely lovely about endlers
Let me start with why I liked them, because there is a lot to like. My Japan Blue endlers were tiny — properly small in a way that makes a little tank feel like a whole world — and that shimmer of electric blue running along their bodies is gorgeous in the right light. They have real presence for such a small fish.
They were also noticeably less inquisitive than my guppies. Where guppies are all over the tank, in your face, searching every corner, the endlers were calmer — present and active, but not constantly demanding attention. They still showed some of those classic livebearer traits, the darting and displaying, just dialled down. If you want the livebearer look in a smaller, more understated package, endlers deliver.
My setup: a filterless ecosystem experiment
I kept my endler trio in a 45 cm long tank with red cherry shrimp, and this was one of my attempts at a filterless tank — a balanced, self-sustaining ecosystem rather than a conventional setup. Plants, Malaysian trumpet snails as the only snail (I deliberately keep MTS-only to avoid a snail population explosion), and the shrimp and endlers as the livestock. The Walstad-style balance is a wonderful thing to aim for, and in many ways the tank worked.
The endlers multiplied happily — that part of the livebearer reputation is completely true. They breed with zero effort. But the half of the ecosystem I most wanted to see flourish never did.
Why my shrimp colony never grew
My cherry shrimp population just would not take off. I had the occasional batch of shrimplets, but I never once got to watch them grow into adults. For a while I could not work out why — and then I started actually watching, closely, the way you have to.
The endlers were harassing my adult shrimp. Not hunting them outright, not at first — just pestering, chasing, nipping. But here is the part that matters: when the harassment got bad enough, the endlers would end up eating the adult shrimp once it had stopped moving. They would pester a shrimp until it was exhausted and motionless, and then it became food. It was not the dramatic predation you might picture — it was slower and, honestly, a bit grim to watch once I understood what I was seeing.
This is the detail I would never have believed from a care sheet: endlers, the "peaceful" tiny livebearer, harassing cherry shrimp into stillness and then eating them. Combined with the fry predation that surely took the shrimplets too, my colony never stood a chance. I was genuinely sad packing it in — I gave the endlers away before I lost more shrimp — but it taught me exactly how this combination really behaves.
Between the adults being harassed and the shrimplets almost certainly being eaten before I ever saw them grow, the shrimp colony simply could not establish. If your goal is a thriving shrimp colony, endlers — like most fish — are not the tankmates for it. Shrimp do best alone or with truly tiny, non-predatory companions. My shrimp guide goes into what actually works.
The honest verdict: cute, but keep them on their own
I came away from endlers with the same conclusion I reached with guppies, which surprised me at the time: they are best kept in a species-only tank. Not because they are bad — they are lovely, and easy, and they breed beautifully — but because their charm comes with that livebearer streak that makes them rough on smaller, gentler tankmates like shrimp.
It depends on your goals, and here is how I would frame it:
- Want a beautiful, easy, self-breeding nano display? Endlers in a species-only tank are fantastic — all the shimmer and activity, no collateral damage.
- Want a thriving shrimp colony? Keep the shrimp on their own. Endlers and shrimp can share a tank, but in my experience the shrimp will not flourish, and adults can end up eaten.
- Want a mixed community? Endlers are gentler than guppies and a reasonable choice with robust tankmates — just not with anything small enough to be harassed.
Cute and adorable, absolutely. But mean in their own quiet way when the tank is small and the tankmates are smaller. Know that going in, give them their own tank, and endlers are one of the most rewarding little fish you can keep.