Halfmoon Betta
Betta splendens
About this strain
The gold standard of fancy bettas for many hobbyists — the caudal fin spreads a full 180 degrees when flared, forming a perfect D-shape or half-circle. Dorsal and anal fins should be large, stiff, and proportional. Look for clean, straight edges with no 'rounding' that drops the spread below 180°. Halfmoons are structurally demanding fish; the finnage can tear easily on sharp decor, and fin rot is a real risk. They're also prone to lethargy — that huge fin is heavy. Keep flow low, temp stable, and water pristine. A well-bred Halfmoon is a showstopper.
Origin
Halfmoons were developed in the early 1990s by a group of U.S. and French breeders, with significant contributions attributed to American breeder Peter Goettner. The 180° standard was formally recognized by the IBC (International Betta Congress) around 1995.