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The double tail variety has two fin lobes rather than one. Also, the dorsal (top) fin has almost twice as many rays as on a single tail (ST) Betta, which results in a much bigger fin. Ideally, both lobes of the tail must be symmetrical. When flaring, the fins almost make a full circle. The DT trait is recessive to ST, and therefore rather elusive. ST bettas who carry the DT gene have dorsal fins that are larger than those ST that don’t carry this gene. If you find the DT trait not appealing, like some breeders do, make sure to ask about the DT gene before purchasing a fish for breeding purposes.

Deltas are characterized by sharp and crisp edges at the ends of the tail (sharpness is a critical factor for Deltas). If the tail is above 130° and lower than 180°, than the term to use is “Super Delta“. A betta is called a “Fantail” if the edges of the tail are rounded. Both the Super Delta and the Fantail are a subgroup of Deltas. These Bettas are much easier to breed than their more coveted brothers, the Halfmoons. Inbreeding is kept to a minimum and the chances of blowing out the tail are small. Some breeders represent their Super Deltas as Halfmoons, therefore, it is important to look for a reputable breeder.

In the Halfmoon tail type, when fully flared, the caudal should be a full 180-degree half-circle. This is due to an increased amount of ray branching. If the tail is larger than 180 degrees, it is known as “Over Halfmoon”. These tails are symmetrical and very heavy.

In crowntail bettas the tail rays extend far beyond the rest of the tail. This gives it a crown-like appearance. The crowntail gene is a recessive gene. There are quite a few crowntail types including Single Ray, Double Ray, and Double Double Ray. Bettysplendens.com has a great article on what makes a good crowntail.

Veiltails are the most common betta tail type. Every fishstore in the world has this kind of betta. Veil tail is a trait… and a very dominant trait – which makes VT’s unfavorable for some breeders. Most betta breeders don’t want to incorporate veiltails in their line. Veiltails are often refered to as “mutts” because of the wide range of colors for the VT’s found in pet stores. In Veiltails the caudel fin rays are not strait and the top rays are shorter than the middle rays, causing the tail to look a little limp.