This document summarizes common parasitic diseases that affect fish and their symptoms and treatment methods. It discusses protozoan parasites like Hexamita that cause holes in the head of fish and helminth parasites like monogenean trematodes that cause gill swelling and scale loss. It also covers annelid parasites like leeches that can cause anemia in fish and crustacean parasites like fish lice that cause skin inflammation. The document provides details on fungal infections like saprolegnia and their white and cotton-like skin growths and describes preventive measures and treatments for various parasitic diseases of fish.

1. SUBMITTED BY : APARNA KUMARI
L-2014-F-07-M

2.  Parasitic diseases are also called as pathogenic
diseases or infectious disease or communicable
disease.
 Important parasitic diseases are protozoan , helminthic
, annelid, nematodes
 and crustacean.
TYPES
ECTOPARASITES: found on the
body surface , fins and
gills.e.g. Argulus , lernea etc.
ENDOPARASITE: Found inside
the body.

3. DISEASE C/O SYMPTOMS
White spot
disease/ich
Ichthyophthriasis
multifilis
Salt like specs on the body and
fins,Excessive slime,Breathing
problem,Loss of appetite.
Trichodiniosis Trichodina spp. Do not eat well,Weakened fish
become susceptible to bacterial
infection
Costiasis Ichthyobodo spp. Heavy breathing,excess mucus
secretion,lethargic,rubbing against
wall.
Hexamitiasis/hole in
head
Hexamita spp. Small holes in head with a tiny
parasite protruding, ulceration of
lateral line, weight loss
Hoferellosis Hoferellus carassii Fluid filled cyst in kidney,unable to
swim.
Neon tetra disease Plistophora spp. Fading of normal brilliant
colour,spinal curvature,weight
loss,equilibrium dysfunction.

4.  Treatment with mixture of formalin and malachite
green (3.3 g of malachite green in 1L of formalin.
It is diluted in 1:40,000.
 Metronidazol @ 5mg/L every other day for three
treatments for controlling Hexamita.

5. MONOGENEAN
TREMATODES
Dactylogyrus and Gyrodactylus
affecting the gills and skin
respectively
SYMPTOMS
•The fish scrapes itself against
objects.
•Gill swollen, pale and show rapid
movement.
•Mucus covering the gills or body.
•Gills or fins may be eaten away.
•Scale loss
DIGENEAN
TREMATODE
Posthodiplostomum and
clinostomum
Fish can be primary or
intermmediate host.
Life stage observed in fish
is metacercaria
SYMPTOMS
•Respiratory problems
•Increased melanin
deposition
•White or yellow spots in
visceral organs

6.  Treatment with potassium permanganate.
 Formalin treatment = 2-4 ml of formalin/10 ml of
water in separate tank for 30 minutes.
 Application of copper sulphate at night (nocturnal
habit of snails).
 Quicklime @ 125-150 kg/acre pond (no fish in the
pond).

7.  Three common nematodes affecting fishes are
Camillanus, Capillaria and eustongylides.
SYMPTOMS
 Infects just about anywhere in the body but only
shows themselves when they hang out of anus.
 Nodules in skin or muscles.
 Stunted growth.
 Abnormal swimming.
 Lethary and death.

8.  Fenbendazol (anti helminth) mixed with fish feed
@0.25% (using gelatin as a binder) for three days.
 Repeat the dose in three weeks.

9.  Major genera : Pisciola and Cystobranchus.
 Leeches are annelid worms with segmented body
having anterior and posterior suckers.
 These are visible on the fish’s skin.
 Heavily infected fish often have chronic anemia.
 Fish can develope secondary bacterial and fungal
infection.

10.  Maintain good hygienic conditions in the pond.
 Disinfect the dried pond with unslaked powdered
lime @ 2500-3000 kg/ha. Fill the water and left for
7-10 days in these alkaline conditions.
 Apply organophosphorus insecticide i.e. Nuvan
(Dichlorvos) @ 0.125 ppm at repeated intervals.
 Apply Gammaxane @ 0.5 ppm as single doze.
 Remove leeches manually from the fish body.
 Bath treatment to fish with 3% salt solution.

12. • Commonly called the "Fish Louse", these are flattened
creatures with a very distinctive shape and appearance.
• They move about the skin of a fish very effectively and
camouflage themselves well on the host.
SYMPTOMS
• Fish rubs itself against objects
• Inflammed areas
• After heavy infestation fish becomes susceptible to
secondary infections.
TREATMENT :Fish can be treated with
organophosphates to control the disease

13. • Commonly called as anchor worm.
• Easily visible to the naked eye and may be more than
2 cm in length.
SYMPTOMS
• Infected fish scrapes against objects, whitish-green
threads hang out of the fish skin with an inflamed area
at point of attachment.
Treatment
• Organophosphates and glacial acetic acid dips
• 10 to 30 minute bath in 10 mg/l of potassium
permanganate.

14.  It is like anchor worm, but is smaller an it attacks
the gills first.
SYMPTOMS
 Fish scrapes against object.
 Whitish or green thread hangs out of fish’s gills
end of the skin.

16. • Causative agent – Saprolegnia
• Opportunistic pathogenic fungi affecting tropical fishes
and fish eggs
Symptoms
• Grayish white, 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.

17.  Causative agent : Branchiomyces demigrans
Symptoms
 Growth of fungus on the respiratory epithelium of
gills causing inflammation and damage to their
blood vessels.
 Infected cells becomes necrotic.
Preventive measures
 It can be controlled with 5% common salt for 5-10
minutes.

18.  Causative agent :Ichthyophonus hoferi
 This fungus causes an internal infection and is generally
chronic and progressive.
Symptoms
 Spores spread to various organs and in severe cases spread out
to the skin which may rupture and become ulcerative at several
places
Preventive measures and treatment
• Removing infected fish and avoiding feeding raw fish products.
• Iodophors of varying iodine concentrations are used to prevent
mycotic infections of nonfood-fish eggs, which can be
disinfected by a 100 ppm iodine bath for 10-15 min.
• Formaldehyde, up to 2,000 ppm for 15 min, can be used to treat
eggs

19. • Causitive agent-Lagenidium sp. Sirolpidium sp. and
Haliphthoros sp
• Filamentous non-septate and coenocytic fungi
• Affected larvae appear opaque followed by sudden
mortality
• Larval stages are highly susceptible
• Black gill disease of larvae is caused by Fusarium sp.
in shrimps.
• Saprolegnia and Leptolegnia cause dark necrotic
lesions on shrimp exoskeleton and cause gradual
mortality.