parasite · both tank

Gill + Body Flukes

Gill + body flukes are flatworm parasites (Dactylogyrus = gill, Gyrodactylus = body) that latch onto fish gills + skin. Cause irritation, scratching, and respiratory distress.

Reviewed by Fast Aquatics husbandry team · Updated May 2026
Severity: Moderate - fatal in heavy infestations

Symptoms

What causes it

Almost always from unquarantined fish. Flukes reproduce rapidly in warm water; one infested fish can spread to a tank in days.

Treatment options

Always treat in a separate quarantine tank.

PraziPro (praziquantel). Standard treatment - safe for most reef + freshwater livestock. 7-day course, 50% water change between doses. Highly effective against most fluke species.
Formalin/malachite (FW only). For freshwater: short bath (1 hour) in formalin solution. Effective but stressful; only for hardy species.
Hyposalinity (SW). Drop to 1.009 SG for 30 days in QT. Less reliable than praziquantel for SW flukes.

Prevention

Quarantine all new fish. Treat with prophylactic praziquantel during QT.

Frequently asked questions

What does Gill + Body Flukes look like?

Rapid gill movement. Flashing or scratching against rocks. Excess mucus production.

What causes Gill + Body Flukes?

Almost always from unquarantined fish. Flukes reproduce rapidly in warm water; one infested fish can spread to a tank in days.

How is Gill + Body Flukes treated?

PraziPro (praziquantel): Standard treatment - safe for most reef + freshwater livestock. 7-day course, 50% water change between doses. Highly effective against most fluke species.

Can Gill + Body Flukes be prevented?

Quarantine all new fish. Treat with prophylactic praziquantel during QT.

How fatal is Gill + Body Flukes?

Moderate - fatal in heavy infestations

Related

Browse the full disease database for 45 aquarium conditions with treatment protocols, or check the care library for prevention-focused husbandry guides. Use our symptom matcher to rank likely diseases from observed signs, the water parameter checker to diagnose related water-quality issues, or the QT timeline calculator to plan a treatment schedule.