Illustration of major parasites of Tilapia, associated clinical signs, epidemiology and possible treatments
 
  PARASITE Disease signs Epidemiology /risk factors Possible treatments
Ciliates Trichodina spp.

(Trichodina in gill wet mount)
 
Erratic swimming Opened operculum Scraping against walls Jumping out of water Erosion of fins, skin ulcers Gill hyperplasia Massive mortality in hatchery and nursery phases Salt bath Formalin bath Hsup2;O² bath KMnO4 bath
Ichthyophthirius multifilis

(Ich on skin wet ount)
 
Appearance of white spots on skin Thick mucus on skin Stunted growth and mortality Most severe in larval stages Problem in recirculation system Repeated formalin bath Increased salinity
Dinoflagellates Amyloodinium spp.

(Trophont in gill filament)
 
Decreased appetite Flashing Accumulation of mucus Brackish water 10-15 ppt Does not occur in freshwater H2O&2bath
Trematodes Digenena (Clinostomum spp)

Metacercariae from wet mount of muscle)
 
Grubs (yellow or white) on the skin. Skin haemorrhage and death if mass penetration of the parasite Occur in pond farming when snails and birds are present Remove or eradicate snails from the pond Prevent bird access to the farm
  Monogenean Dactyolgyrus spp

(Adult on skin wet mount)
Skin darkening Fin erosion Excessive mucus Rapid movement of operculum Emaciation in young fish Juvenile and fingerling stages Formalin bath H2O2 bath
 
Argulus sp.
(adult from fish skin)
 
Skin irritation Loss of condition Associated secondary skin bacterial infection Severe in larval stages and fingerlings Organophosphates
Crustaceans Copepods Lernea spp.

(adult from fish skin)
 
Rub against sides of container Whitish spots of curled up worms embedded in the skin Can affect mouth breeding Organophosphates
Hirudidae Leeches

(adults on skin of fish)
 
High number of leeches on an adult fish induce anemia Severe in early stages Affect fish already weakened by another disease Organophosphates