The body length of betta fish is generally between 3 and 10 centimeters.
Betta fish belong to the family Osphronemidae of Perciformes. Their body shape is oval, laterally compressed, and the abdomen is in a wide arc. The body length of adult fish is usually between 3 and 10 centimeters, and the weight is between 1 and 6 grams. Male individuals are usually slightly larger than female individuals, and the body color is also more vivid. The caudal fin can be forked or round.
The body length and weight of betta fish will vary depending on their species and living environment. For example, the body length of Siamese fighting fish is generally 3 to 4 centimeters at 3 to 4 months of age, and 4 to 6 centimeters at 4 to 8 months of age; the body length of Chinese fighting fish is generally 3 to 4 centimeters at 3 to 4 months of age, and 5 to 7 centimeters at 4 to 8 months of age.