You might need to know that people have classified Betta Splendens based on the shape of its tail. Here's the list:

• Half-moon (large tail fin that forms a 180-degree or larger circle segment)

• Short-finned fighting style (sometimes called "plakat")

• Double-tail (the tail fin is split into two lobes and the dorsal fin is significantly elongated)

• Delta tail (tail span is less than half-moon with sharp edges)

• Fantail (a rounded delta tail)

• Veiltail (non-symmetrical tail, only two rays)

• Crowntail (highly frilled, extended spiny rays)

• Combtail (less extended version of the crown tail)