Fish Lice

Just like ich, fish lice can be observed in freshwater and marine environments, though they are caused by different species of animals. They have a fairly simple life cycle that takes a minimum of 3-6 weeks, depending on the exact species. They are not zoonotic. 

Symptoms

The most easily identified symptoms of lice are the lice themselves. However, there will be other symptoms before such as Flashing due to the intense irritation these crustaceans cause. Some fish will attempt to jump to soothe their itch. 

Treatment

Treatment is pretty easy with lice. Because they are invertebrates, they are susceptible to copper. After dosing with copper, manual removal of the adult lice will also aid in the fight. Copper should be in the water for no less than a week to make sure that all the eggs have a chance to hatch and die off.