Fish factor

• Most fish diseases are caused by microbes, parasites, etc. that cause disease.

• In addition, there are animals that predate fish and animals that are dangerous to fish, such as water birds, water snakes, aquatic insects, etc.

• Internal factors in fish: Fish's resistance to and immunity from infection vary depending on their species and age.

• When raising multi fish species together in the same pond, the grass-eating carp has enteritis with silver carp and the big head carp do not have this disease.

• Carp less than 5 cm long are more likely to have whitehead or white mouth disease, but grass-eating carps greater than 5 cm long do not have this disease.

• The resistance of fish to disease depends on the species, its habitat and diet, and the health status.

• Therefore, to clearly understand fish diseases, it is necessary to understand the external and internal factors of the fish to find the cause of the disease in the fish.