Carassius auratus lost a lot of weight after spawning. Carassius auratus lost a lot of weight after spawning for the following reasons:

1, crucian carp will consume a lot of energy when laying eggs, so it may lose weight after laying eggs.

2. In addition, crucian carp will eat less when laying eggs, which will also lead to weight loss. So crucian carp lost a lot of weight after laying eggs. Crucian carp is a common freshwater fish, belonging to CYPRINIDAE. They live in rivers, lakes and reservoirs in the south of China and are also farmed artificially.