Can Endler's livebearer live with Harlequin rasbora?

Temperature. Endler's livebearer does best at 24–30 °C (75–86 °F) and Harlequin rasbora at 22–25 °C (72–77 °F). They share 24–25 °C.

Water. Their pH ranges overlap at 7–7.

Temperament and size. Endler's livebearer is peaceful and grows to 2.5 cm; Harlequin rasbora is peaceful and grows to 4.5 cm. Endler's livebearer swims at the top and Harlequin rasbora at the mid, which spreads them out.

Tank size and groups. Plan on at least 15 US gallons, the larger of the two cautious minimums. Keep Endler's livebearer in a group of 3+. Keep Harlequin rasbora in a group of 8+. A starter mix of 3 Endler's livebearer and 8 Harlequin rasbora in 15 gallons uses about 73% of the tank’s bioload capacity under our rules and grades A.

Keeping them together

• Feeding: both feed in open water. Feed small amounts two or three times a day so the slower eater gets its share.
• Aquascape: both are calmer with cover. Plants and floating cover make shy fish come out more, not less.
• Group size: a full group is not optional. A schooling fish kept in too small a group is stressed and more likely to nip or hide.
• Adding them: add the calmer species first and let it settle for a week or two before adding the other, and only once your tank has cycled.

Open this pair in the checker Add your other fish to grade the whole tank.

Quick facts

Data from the Species Ledger, checked November 9, 2026, with at least two sources per species. Cautious community guidelines, not guarantees: individual fish vary. Not veterinary advice. Disagree? Tell us.