FUNGAL_DISEASES in fishes and the effect.

Fishes diseases in

1. FUNGAL DISEASES

2. Cotton wool disease
•Causative agent –Saprolegnia
•opportunistic pathogenic fungi affecting tropical fishes and
fish eggs
Symptoms
•greyishwhite, cotton-like growths on the skin, gills, eyes, or
fins that may invade deeper tissues of the body.
preventive measures
•removal of predisposing causes, e.g. inadequate sanitation,
excessive chemical treatment, or the presence of dead,
infected fish and decaying organic material.

3. Ichthyophonushoferi
•This fungus causes an internal infection and is
generally chronic and progressive.
Preventive measures
•removing infected fish and avoiding feeding raw
fish products.
•Iodophorsof varying iodine concentrations are
used to prevent mycoticinfections of nonfood-
fish eggs, which can be disinfected by a 100 ppm
iodine bath for 10-15 min.
•Formaldehyde, up to 2,000 ppmfor 15 min, can
be used to treat eggs

4. Larval mycosis in shrimps
•Causitiveagent-Lagenidiumsp. Sirolpidiumsp. and
Haliphthorossp
•filamentous non-septateand coenocyticfungi
•Affected larvae appear opaque followed by sudden
mortality
•Larval stages are highly susceptible
•Black gill disease of larvae is caused by Fusariumsp. in
shrimps.
•Saprolegniaand Leptolegniacause dark necrotic
lesions on shrimp exoskeleton and cause gradual
mortality.

5. Epizootic Ulcerative Syndrome (EUS)
•Cause damage to a wide variety of fishes (most affected are
murrels) but chineese carp and tilapia relatively resistant
•Causitive agent-Aphanomyces invadans.
•Infection starts as a red spot in the skin then it eventually
becomes an ulcer and finally resulting in erosion of
ulcerative area.
•Disgnosis:-Grocott’s stain is used for fungal staining. It gives
black colouration in the fungal hyphae.
•A. invadanshas the ability of penetrating the body of the
fish using the proteolytic enzyme
It causes mortality by two means
(i) by invading fungus
(ii) osmoregulatory failure of invaded area

6. Contd…..
Control Measures
•Intheinitialstage,applicationoflimeandsodium
chloridetreatmentwasfoundtobeeffective.
•CIFAproducedamixtureofCIFAX,forcontrollingEUS
butnotmuchstandardized.
•Treatingthewaterwithchlorinebeforelettinginto
thepond,avoidanceofwaterusefromlargewater
bodywithimproperwaterquality,useoffiltersin
waterchannelstoavoidwildfishentryand
preventingtheentryofpredatorybirdsarecentralto
diseasemanagementstrategy.