Argulus Fish Lice of Goldfish, Koi and Aquarium Fish

Fish Lice: Argulus Parasite, How To Treat Fish Lice

Argulus aka Fish Lice

Fish Lice, or Argulus

Different names for the same parasite. This is a crustacean parasite, meaning it’s a lot like a little crab. Little? Yeah, it’s about 1/4 inch in diameter and they are EXTREMELY agile. I’ve Youtube’d a movie with these, so you can see it.

This parasite is commonly seen in the Fall of the year. Folks call me and say “My fish has a freckle.”

Hmmmm A freckle? Well that happens sometimes it’s called Shimi, and hard water causes it.

The next day, they call back. “Remember that freckle? Well it moved.”

So, moving freckles…..Argulus!

Argulus Fish Lice of Goldfish, Koi and Aquarium Fish
Argulus Fish Lice of Goldfish, Koi and Aquarium Fish

Here again, if you can see the parasite, you can kill it with Dimilin. Dimiln’s wonderful stuff but sometimes hard to get. As of this writing there’s probably 3-4 different commercial “Dimilins”.

Here are links from 2018:  MicrobleLift_Anchor_Worm     and  CyroPro from Hikari

I discovered *another* completely safe treatment you can get from your local Vet for about four bucks – (Program) but all the open-minded ‘non doctors’ in rec.ponds once assured everyone that it would kill your fish, (of course they did not even try it) and the company that makes it would rather not have it mentioned. It’s one “White” (large) Program Tablet (Lufenuron) per thousand gallons. Dose is not critical however because the medicine is extremely safe.

Dimilin is dosed at 0.5 to 1 ppm or one gram per thousand gallons. Despite dire warnings from experts who ever tested it (like I have) Program, which has been used effectively now for SEVENTEEN years works great.

-Erik Johnson