Here's why it happens:
* Instinct: Angelfish, like many other fish, have an instinct to eat anything that looks like food. Newly hatched fry can be mistaken for food by their parents, especially if they're stressed or hungry.
* Lack of experience: First-time parents might be less experienced in recognizing and protecting their fry.
* Poor water quality: Stressed fish due to poor water quality are more likely to become aggressive and eat their fry.
How to prevent angelfish from eating their babies:
* Provide ample hiding places: Dense plants, caves, and other hiding spots give the fry a chance to escape their parents.
* Separate the parents: You can temporarily move the parents to a separate tank until the fry are bigger and less vulnerable.
* Feed the parents well: A healthy diet will reduce the chance of them becoming hungry and eating their young.
* Use a breeder box: A breeder box allows the fry to grow in a separate, safe environment.
* Condition the parents: If you're planning to breed angelfish, condition them with nutritious foods and proper water quality to increase the chances of successful breeding and parental care.
Remember, angelfish are not naturally the most attentive parents, and it takes careful planning and management to ensure the survival of their fry.