Over Half Moon (HM) Betta
When a tail spread between the top and bottom tail rays gets to the 180 mark, the fish is designated a Halfmoon Betta.
But when breeding for that kind of branching and tail spread, some Bettas had a spread that exceeded the 180 degree mark.
These extreme Half Moon Bettas were given the term; Over Half Moon when tails had more than a 180 degree spread.
The Over Halfmoon Betta or OHM, is the extreme end of the Halfmoon where the spread of the fins when flared, is over 180 degrees.
The OHM tail can apply to both Long Fin Halfmoon and the Halfmoon Plakats.