Double tail betta

A double tail betta male is a variant of the Betta splendens, or Siamese fighting fish, that is distinguished by its unique, split tail, featuring two distinct lobes instead of one. These fish are known for their vibrant colors, flowing fins, and territorial behavior. 
Here's a more detailed look:

Split Tail:
The defining characteristic of a double tail betta is its tail structure, which appears to be a single tail split into two lobes. 
Vibrant Colors:
Like other betta varieties, double tail males come in a wide range of colors, often with metallic or iridescent sheens. 
Long Fins:
Their dorsal, anal, and pectoral fins are also long and flowing, adding to their elegance. 
Short, Stout Body:
The double tail structure necessitates a wider base for the tail, resulting in a shorter, stouter body profile compared to other betta types. 
Territorial:
Like all male bettas, double tail males are territorial and may be aggressive towards other males.