Brooklynella hostilis
What You Need To Know:
* This is most often seen in clownfish, but it can afflict any fish. The fish’s skin will appear to be peeling or sloughing off, oftentimes causing excessive white mucous to form around the affected area(s).
* Treatment of choice is a 45 minute formalin bath (e.g. Quick Cure), followed by transfer into a new/sterile QT.
* The fallow (fishless) period for starving Brook out of a Display Tank is 6 weeks.
Early stages:
More advanced stages:
Brook on a Naso Tang (notice how it presents differently on non-clownfish):And on this Purple Tang:
Additional Information
Brooklynella hostilis is a ciliate parasite with a direct life cycle: It lives, feeds and reproduces directly on the fish (no encysted stage). However, there always exists the possibility that parasites can drop off into the water column and infect other fish. Having no encysted stage makes this pathogen easier to eliminate, but do not underestimate how fast killing Brook can be. Especially with clownfish.
Treatment Options – Formalin is the most effective treatment for Brook, but using Ruby Reef Rally is another good option. Both are best applied via bath treatment, and more information on this can be found in the links below.
Formalin (45 min bath): https://humble.fish/formalin/
Rally (90 min bath): https://humble.fish/acriflavine/