Betta fish do possess the ability to breathe air, thanks to their unique physiological structure. Below are the key points:
1. The Core Organ for Air Breathing: Labyrinth Organ
Betta fish have a labyrinth organ (also known as a folded gill or maze organ), which allows them to gulp air directly from the water surface. This organ then transfers oxygen from the air into their bloodstream.
This trait enables betta fish to survive in low-oxygen water environments (such as rice paddies and stagnant ponds) and even stay alive for short periods out of water (e.g., during transportation).
2. Synergy Between Breathing Methods
Gill Breathing: This is their regular underwater breathing method, but its efficiency is affected by water temperature and dissolved oxygen levels.
Labyrinth Breathing: Serving as an auxiliary breathing method, it becomes the main source of oxygen supply when water oxygen levels are low or the water temperature is high (>28°C).
Skin Breathing: Betta fish absorb oxygen from water through the dense capillaries in their skin, and this method is particularly effective in low-temperature environments.
3. Performance in Practical Care
No Need for Aeration: Since they can breathe air directly, Thai betta fish typically do not require additional oxygenation equipment in home aquariums.
Surface-Gulping Behavior: Frequent trips to the water surface to breathe are a normal behavior and not a sign of oxygen deprivation.
4. Precautions
Water Temperature Control: The efficiency of labyrinth breathing decreases when the water temperature exceeds 28°C, so high-temperature environments should be avoided.
Water Quality Management: The ammonia concentration in the water must be kept below 0.2mg/L; otherwise, it may impair the fish’s respiratory function.
The air-breathing ability of betta fish is an evolutionary advantage that helps them adapt to harsh environments. However, proper care is still necessary to maintain their health.