According to search results, the average lifespan of bettas varies depending on their species, gender, and rearing conditions. Here is a summary of the key information:

Siamese Fighting Fish Lifespan
Average Lifespan: 2-3 years, with males typically living longer than females (3-6 years for males, 2-3 years for females).
Special Cases: Under ideal rearing conditions, some male Siamese fighting fish can live up to 8 years, though this is extremely rare.
Influencing Factors: Water quality, temperature, rearing methods, and innate physical condition have a significant impact on their lifespan.
Chinese Fighting Fish Lifespan
Average Lifespan: Generally 2-3 years, with males potentially living 3-5 years in a suitable environment.
Aging Characteristics: They are most visually appealing at 1 year old; after 2 years, they gradually fade in color and lose vitality.
Common Patterns
Gender Difference: Males generally have a longer lifespan than females.
Key Rearing Tips: It is necessary to maintain clean water and stable temperatures (e.g., 25-28°C), and avoid overbreeding or direct exposure to strong light.
Aging Signs: After 2 years, their ornamental value decreases, their body color fades, and their activity level reduces.
To extend the lifespan of bettas, it is recommended to select healthy individuals, provide a stable environment, and regularly observe their condition.