Long fins selections in which dorsal, caudal and anal fins (primary fins) form a semicircle similar to an halfmoon, hence the name.
To be defined Halfmoon a Betta must have a caudal fin with a minimum extent of 180°; specimens with a greater extent are called Overhalfmoon (see below).
In this selection is particularly important the simmetry: the three forenamed fins should be ideally the same lenght, making possible to draw a perfect circle around the fish.
And that is the aspect of the Overhalfmoon.
These specimens are considered as an Halfmoon’s variation.
They present an excessive branching towards the end of the tail; also the webbing between the rays results exaggerated and often folded over itself.
These characteristics make the tail looks like rose petals, hence the name.
Another variation of Halfmoon very similar to the Rosetail one.
In this case the excessive branching not only occurs towards the end of the tail but from the beginning.