Tail types of Betta Imbellis

The Halfmoon 
Considered the ideal show form, the Halfmoon tail spreads 180 degrees with straight caudal edges and even ray branching
The dorsal, anal and caudal should ideally demonstrate the same length.

The Double Tail
Two evenly split lobes of the caudal, the double tail should be split all the way to the base of the tail.
The dorsal on the DT is typically larger at the base and should reflect the anal fin symmetrically.
The double tail occurs in all fin types.

The Rose Tail
Shows excessive branching in the tail and all three inpaired fins, and creates an overlapping giving a 'rose like' appearance. 

The Veil Tail 
An asymmetrical tail design, ideally with an upward arch at the top and graceful drop downwards
This is the type of Betta commonly found in pet stores.

The Round Tail
A fish with uneven symmetrical branching, showing a rounded edge to the caudal.

The Delta Tail
Demonstrating a symmetrical structure, each ray is the same length, creating a sharp edged > shape, with a spread between 150 - 164 degrees.

The Super Delta Tail
An extension of the Delta, with a spread of between 164-179 degrees, again demonstrating straight caudal edges.

The Spade Tail
Not as common as they once were, the spade demonstrates a symmetrically wide base, narrowing to a point.

The Crown tail
Available in all tail shape types, the crown demonstrates reduced webbing between the rays, show standards ask for a reduction of 50% 
Shown to the right is a fish with single ray reduction.

The Double Ray Crowntail
Showing an alternating degree of reduction every two rays.

The Feather Tail (OHM)
Demonstrating feather-like branching from each main ray. A mutation from the rose tail, with excess finnage.

The Apache Tail (New)
A further mutation from the feather tail, clear branching shown from the main rays in the caudal.

For more on the IBC show standards click here