Fish & shrimp health guide
Vorticella & Scutariella (Shrimp Parasites)
Also called vorticella, scutariella japonica, shrimp fungus
White fuzzy or thread-like growths on the shrimp's nose, head or shell, sometimes waving in the flow.
TL;DR, Vorticella & Scutariella (Shrimp Parasites)
These are the little white growths people mistake for fungus on shrimp. Vorticella looks like a white fuzzy mould on the shell and appendages, while Scutariella japonica shows as tiny white threads on the shrimp's nose and head. Both are external hitchhikers that thrive in mucky water, and both are treatable, unlike internal infections. A salt dip or an invert-safe treatment clears them, and keeping the water clean stops them returning. They usually arrive on new shrimp, so quarantine helps.
What you see
For vorticella, a white fuzzy or f-shaped growth on the shell, legs or rostrum that can wave in the current. For scutariella, small white threads or bristles on the nose and head, sometimes with the shrimp scratching. The shrimp otherwise grazes and behaves normally at first.
What causes it
- Poor water quality and high organic waste feeding the organisms
- New shrimp introduced without quarantine bringing them in
- An overstocked or under-maintained tank
How to treat it
- Improve water quality first, since both thrive on organic muck.
- For a light case, a brief salt dip outside the tank can knock them off, following a shrimp-safe method.
- For scutariella, an invert-safe treatment (for example a suitable planaria and parasite remedy at shrimp doses) clears it.
- Repeat as directed, and treat new arrivals in quarantine.
- Keep up maintenance so they don't come back.
Treatment safety in a planted tank
Skip copper and harsh fish parasite meds, which kill shrimp. Use a salt dip done carefully outside the display, or a treatment explicitly rated shrimp-safe, and dose to shrimp tolerances, not fish ones.
Prevent it
Quarantine new shrimp, keep the water clean, and don't overstock. These parasites need mucky conditions and an unquarantined carrier to take hold.
Easy to confuse with
Both are mistaken for a fungal infection. Fungus is unusual on live, healthy shrimp; white growth on the nose is almost always scutariella, and fuzzy shell growth is vorticella, both of which are treatable.
Species most at risk
Species that catch this most often, or that need a gentler treatment:
Frequently asked questions
Direct answers to the questions search engines and AI assistants surface most often about this species.
Is the white stuff on my shrimp's nose fungus?
Almost certainly not. White threads on the nose are Scutariella japonica, a treatable external parasite, not fungus.
Will it spread to my other shrimp?
It can, so treat the tank and quarantine new arrivals. Clean water slows it right down.
Is a salt dip safe for shrimp?
A short, correctly done dip outside the tank is a common treatment for light cases, but follow a shrimp-specific method carefully, since shrimp are far less salt-tolerant than fish.