The questions to ask a fish shop before getting a least killifish are shaped by two facts: this is one of the smallest livebearing fish in the world, and a healthy group quietly multiplies. Origin, sex mix, food size, and a plan for the babies matter more for this species than for almost any other fish of its price, and a good shop — often one that breeds them on the premises — will welcome every question.
Are these least killifish locally bred, wild-caught, or farmed?
Least killifish are native to slow, plant-choked waters in the southeastern United States, and shop stock may be home-bred, locally collected, or raised by small-scale breeders rather than large farms, so ask where the fish in the tank actually came from. Home-bred and locally raised fish usually arrive already adapted to local water and aquarium food, while collected fish may need more settling and, depending on where you live, collection rules may apply to how they were obtained. Ask how long this group has been with the shop and whether it is the shop's own breeding colony on display. A colony that has lived and bred in the shop's water for months is about the lowest-risk purchase in the entire fish department.
What sexes am I looking at, and is the group already breeding?
Sexing least killifish is easy once shown — males are smaller with a modified anal fin, females larger and rounder — so ask the staff to pick you a deliberate mix rather than a random scoop, usually more females than males so no single female is courted constantly. Then ask whether this group is already producing fry in the shop tank. If babies are appearing among the plants, you are buying a proven colony whose conditions clearly suit it, and you should expect the same at home within weeks. That expectation drives the last big question below, so note the answer. A group that has never bred in the shop may simply be young — ask its age before drawing conclusions.
What do you feed fish this small, and what should I feed the fry?
Least killifish adults take fine powdered food, crushed flake, and micro-pellets, and graze micro-organisms from plant surfaces between meals, so ask what this group is fed and how it responds. The more specific question concerns the fry: newborns are tiny even by livebearer standards and do best on infusoria-type foods, powdered fry food, and the natural micro-life of a mature planted tank. Ask whether the shop sells a suitable fry food and whether its own fry survive in a planted display without special feeding — in a well-grown tank, many do, which tells you how much intervention your setup will need. Buying the adults' current food with the fish keeps the first week familiar while the colony settles.
Will you take surplus fry, and who can they live with?
A settled least killifish colony produces a slow, steady stream of fry, and within months a small tank can hold more fish than it should, so ask the shop before buying whether it accepts surplus youngsters for store credit or rehoming. Shops that breed the species usually say yes gladly; knowing the answer in advance turns a future overcrowding problem into a pleasant arrangement. Round out the conversation with tankmates: least killifish are peaceful but easily outcompeted and their fry are snacks for anything large enough, so ask which companions the shop pairs them with — small shrimp and snails are the usual recommendation, with other fish best kept to a species-only setup.
A fish that costs little and breeds freely asks more planning questions than purchasing questions, and the Pet Services Directory in KinsLe helps you find local shops that breed least killifish themselves and can answer every one of them.