Here's what you should do:
1. Consult a veterinarian: The best course of action is to take your betta fish to a veterinarian specializing in aquatic animals. They can assess the severity of the damage and provide appropriate treatment.
2. Clean the tank: Make sure the tank is clean and free of any potential irritants or bacteria. This can help prevent further damage and promote healing.
3. Isolate the fish: If there are other fish in the tank, isolate the injured betta to prevent aggression or further injury.
4. Provide appropriate conditions: Maintain a stable temperature, good water quality, and a stress-free environment.
5. Monitor the fish: Watch for any signs of infection or further deterioration, such as redness, swelling, or lethargy.
Healing time:
* Minor damage: Shredded fins can often heal on their own with good care. However, it may take several weeks.
* Severe damage: If the fins are extensively damaged, healing might be slower and require treatment.
* Fin rot: This bacterial infection can cause extensive fin damage. Prompt veterinary care is essential.
Prevention:
* Tank mates: Betta fish are generally solitary creatures and can be aggressive towards other fish. Consider keeping them alone or with very peaceful tank mates.
* Decor: Avoid sharp objects in the tank that could injure the fish's fins.
* Water quality: Poor water quality can stress the fish and make them more susceptible to infections.
Remember, a veterinarian is the best resource for advice on your betta's specific condition and how to help it heal.