Common Name:  Anchor Worm

Pathogen/Cause: Lernea spp.

Physical Signs: Actually, lernea is a copepod (crustacean arthropod) rather than a true worm. It looks like a small whip (a few mm to under an inch long) attached to the fish at the mouth end and with a forked tail.

Behavioral Signs: Usually none noted unless very severe with secondary infections.

Potential Treatment: May be physically removed, but will cause great stress to the animal, and must be done carefully and with a dab of antibiotic over the wound afterwards. Brand name formulations like Jungle Parasite Guard and Aquarium Pharmaceuticals may also help.

Other Notes: Rarely seen in pet fish not kept outdoors (in ponds), and usually then only in ones that have been fed live foods.

Common Name:  Fish Louse

Pathogen/Cause: Argulus spp.

Physical Signs: A flat disk-shaped arthropod parasite with many legs. On the fish itself it is barely noticeable only as a flat, dull colored bump that you may just think is a part of the fish, unless you see the legs themselves or the disk moving around on the body.

Behavioral Signs: Usually none noted unless very severe with secondary infections.

Potential Treatment: May be physically removed, but will cause great stress to the animal, and must be done carefully and with a dab of antibiotic over the wound afterwards. Brand name formulations like Jungle Parasite Guard and Aquarium Pharmaceuticals may also help.

Other Notes: Rarely seen in pet fish not kept outdoors (in ponds), and usually then only in ones that have been fed live foods. Crustacean not related to true lice, which are insects.