Species feeding guide

Live food for rasboras

Rasboras are the nano-tank’s schooling fish — and nano mouths need nano food. Adults hunt small crustaceans all day in the wild, so moina-sized daphnia is a perfect staple-size live feed, while their fry start smaller than most keepers expect and need the worm-and-eel end of the culture shelf.

Harlequin rasboras schooling in a planted aquarium

Photo: Tucsouffle, Wikimedia Commons, CC BY 2.5

The feeding plan

Stage	Feed this	Why it works
Adults, regular feeding	Live daphnia (moina), a few times a week	Adult moina (±1–1.5 mm) fits even chilli and dwarf rasbora mouths; hunting a scattered feed is the behaviour these fish are kept for
Conditioning for spawning	Daphnia + microworms in rotation for 1–2 weeks	Harlequins and lambchops spawn far more readily on live food; females visibly fill out
Fry, first week	Vinegar eels	Rasbora fry are tiny; eels swim at the surface film where the fry hunt and stay alive between feeds
Fry, weeks 2–4	Microworms, then newborn moina	The size ladder up to the growth phase — keep both running so the smallest fry are never stranded

Practical tips

Scatter daphnia across the tank rather than in one spot — a whole school hunting at once is the rasbora display at its best.
For breeding harlequins, feed live food and keep up soft, clean water; they spawn under broad leaves when conditioned.
Pencilfish (sold alongside rasboras) feed identically — small moina for adults, eels and microworms for fry.

Watch out: Do not judge feeding by the boldest fish. In a rasbora school the shy ones hang back; scatter food widely and watch the whole school’s bellies, not the front row.

Common questions

What do rasbora fry eat?

Vinegar eels for the first week — small enough and swimming where fry hunt — then microworms, graduating to newborn daphnia (moina) from about week 3.

Is daphnia too big for rasboras?

True Daphnia magna can be, which is why ours is moina: adults are ±1–1.5 mm and newborns much smaller, suiting even dwarf and chilli rasboras.

How often should rasboras get live food?

Two to four small live feeds a week alongside a nano pellet or crushed staple keeps colour and behaviour at their best; condition daily for 1–2 weeks before a spawning attempt.