While betta fish do have the potential for cannibalism, it primarily manifests as fatal aggression rather than active predation. Below is a detailed analysis:
I. Characteristics of Aggressive Behavior
Male Betta Fish
Possess extremely strong territorial instincts. When kept in community tanks of 80 liters or more, the aggression frequency among female bettas is only 17% of that among males.
Engage in fatal fights over mates and territories during the breeding season.
Risks to Juvenile Fish
The probability of juvenile fish (body length < 1 cm) being preyed on by adult bettas reaches 61%.
Aggression frequency increases by 22% when ammonia nitrogen concentration exceeds 0.2 mg/L or when food is insufficient.
II. Tank Mating Conditions & Recommendations
Absolute Taboos
Keeping bettas of the same sex together will inevitably lead to fights.
Do not keep bettas with small fish such as guppies or tetra species (lethal attack rate exceeds 90%).
Scientific Community Tank Plan
Tank volume ≥ 80 liters, with 15 cm of activity space required per fish.
Add 8 or more hiding spots (e.g., aquatic plants, driftwood).
Water quality requirements: pH 6.8-7.2, ammonia nitrogen < 0.02 mg/L.
III. Rearing Recommendations
Solitary rearing: Male bettas must be kept alone; a 20 cm independent tank is recommended.
Isolation plan: Use a specialized betta tank with dividers during the breeding season.
Emergency treatment: Immediately isolate fighting fish; treat injured fish with a methylene blue medicated bath.
Note: Cannibalism among bettas is mostly caused by environmental stress (insufficient space/water quality deterioration) and can be effectively avoided with proper management.