A Mixed Micro Diet Suits the Least Killifish
A least killifish should eat a varied mix of finely crushed staple food, tiny live or frozen items, and grazeable plant matter every day. Adults pick insects and larvae from the surface, browse algae and biofilm from leaves, and take almost any food small enough to fit a mouth that makes standard pellets look like boulders.
Crush flake to a coarse powder or choose genuine micro food as the base, then rotate the animal portion across the week: baby brine shrimp one day, daphnia or microworms another, finely crumbled frozen food in between. The plant side needs no special serving — a mature planted tank with algae on leaves and hardscape is itself part of the diet, and least killifish spend much of the day working it over between the meals you provide.
One Diet Must Feed Adults and Hidden Fry Together
A least killifish colony always contains fry, and the everyday diet has to reach them without a separate feeding regime. Powdered staple dusted into the plant thickets serves them, while the adults take the larger crumbs at the surface from the same pinch.
This is why a least killifish tank should never be scrubbed sterile or fed only in open water. Sprinkling part of each feed directly over the plant cover, and keeping a patch of soft algae growing on the glass or a stone, gives the youngest fish a continuous food source between your measured meals — the difference between a self-sustaining colony and one that slowly stops replacing itself.
Surface Feeding in a Quiet, Planted Setup
A least killifish feeds best where the water is calm and cover is close. These are shy fish from still, vegetated waters, easily outcompeted and easily startled, so food dropped in strong flow or in a bare open corner may go untouched while the colony watches from the plants. Offer food at the surface above their thicket, in small amounts several times rather than one large dump, and let it drift slowly among the stems.
Tankmates change the menu's delivery more than its contents. With peaceful nano fish of similar size, least killifish hold their own at the surface. Beside larger or boisterous fish they retreat, and both adults and fry go hungry in a tank that appears well fed. If the colony shares its home, feed the other fish at the far end first, then tend the killifish thicket as its own separate station.
Amounts for a Fish That Grazes All Day
A least killifish needs small added meals because so much of its diet is already growing in the tank. Watching bellies helps: females carrying fry look naturally deep-bodied, so judge by behaviour — a colony that grazes calmly and rises for food is fed; one that crowds the surface desperately at every approach may be short.
Overfeeding is the quieter risk in a least killifish setup. Powdered food is easy to overdose, and excess dust decaying in dense plants fouls the still water this species prefers. If crushed food still clouds the surface after a few minutes, the pinch was too big; cut it and split the difference into an extra tiny feed later rather than letting leftovers rot among the fry's shelter.
Recording a Colony Diet That Has Several Parts
Least killifish feeding has more moving parts than most — crushing, dusting the plants, rotating live foods — and a helper given vague instructions will usually just add flake. A written duty that names each part keeps fry and adults fed the same way whoever is on duty. In KinsLe, Care Teams can list the colony's daily feeds as assigned tasks with the food for that day specified, each marked complete with a timestamp so the next helper knows the fry thickets were dusted too.