Vorticella on Shrimp: The 'Mold' That Isn't Fungus
Vorticella is a stalked, bell-shaped protozoan that colonises shrimp as a white, fuzzy, mold-like growth — but it is not a fungus. Learn how to tell it apart from Scutariella and true fungus, and how salt baths and a clean molt clear it.
What Vorticella is
Vorticella is a bell-shaped ciliated protozoan (order Sessilida, family Vorticellidae) that lives on a contractile stalk and can retract rapidly. It is a sessile suspension feeder that beats its oral cilia to draw in bacteria and particles, and it frequently attaches to crustaceans and other aquatic animals as an epibiont.
Telling it apart
On shrimp, Vorticella appears as a white, fuzzy, fungus-like or mold-like growth on the exoskeleton or rostrum. Unlike Scutariella it is not a discrete worm but a colony of stalked protozoans, and unlike a true cotton-wool fungus it is a stalked ciliate. It tends to colonise weak or molting-impaired shrimp and thrives in poor water quality.
Treatment
- Improve water quality first — it is the root driver, and it supports healthy molting.
- Give an individual salt bath using aquarium (non-iodized) salt, as for Scutariella, repeated over several days.
- Let a healthy molt shed the attached colony.
- Avoid copper and iodized salt entirely.
UF/IFAS salt-therapy guidance supports salt baths as a safe anti-parasite measure at controlled concentrations and durations, which is why the shrimp salt dip is the recommended tool here.
Sources: en.wikipedia.org (Wikipedia, CC BY-SA 4.0); www.theshrimpfarm.com ; ask.ifas.ufl.edu (UF/IFAS VM007)