Can harlequin rasboras and male bettas live together?

Yes

Harlequin rasboras and male bettas can share a tank. Their water needs overlap and neither is known to bother the other.

Harlequin rasbora Betta (male)

Why

  • Their temperature and pH ranges overlap comfortably, and neither is known to nip, chase or eat the other.

What each one needs

Harlequin rasboraBetta (male)Both
Temperature72–80°F (22–27°C)76–82°F (24–28°C)76–80°F (24–27°C)
pH6.0–7.56.5–7.56.5–7.5
Minimum tank10 gal (38 L)5 gal (19 L)10 gal (38 L)
Keep at least61
Adult size1.8 in (4.6 cm)2.5 in (6.4 cm)

The smallest tank for both

A 10 gallons (38 L) tank holds 6 harlequin rasboras and 1 betta (male) at about 80% of its stocking limit, which leaves room for more.

Other tank mates for harlequin rasboras

Other tank mates for male bettas