Like humans and other animals, fish suffer from diseases and parasites. Fish defences against disease are specific and non-specific. Non-specific defences include skin and scales, as well as the mucus layer secreted by the epidermis that traps microorganisms and inhibits their growth. If pathogens breach these defences, fish can develop inflammatory responses that increase the flow of blood to infected areas and deliver white blood cells that attempt to destroy the pathogens. Specific defences are specialised responses to particular pathogens recognised by the fish's body, that is adaptative immune responses.[3] In recent years, vaccines have become widely used in aquaculture and ornamental fish, for example vaccines for furunculosis in farmed salmon and koi herpes virus in koi.[4][5]

1. NAME: MUHAMMAD AAMIR BILAL
SEMESTER: 7th
ROLL NO: 35
PRESENTATION TOPIC: DISEASES OF FISH

2.  Fish diseases may be infectious or non
infectious
 Infectious includes;
 Viral borne
 Bacterial
 Fungal
 Trematodes
 Cestodes
 Nematodes etc.

3.  Non Infectious includes;
 Anoxia
 Gas Bubble Disease
 PH disturbacnce
 Dietary
 Intoxications
 Toxic Algae

4.  Infectious:
 1.Viral:These are further divided into;
 (a)Lymphoycstis:It is characterized by the
formation of proliferous growth of connective
tissue in the skin,resuting into warts.
 It is not lethal but may cause secondary fungal
infections
 Symptoms:tumors or warts on the body.
 Treatment:no cure;fish should be destroyed

5.  (b)viral haemorrhagic septicaemia(VHS):this
disease is mainly found in rainbow trout farm.
 It suddenly becomes chronic and mortality is
very high.
 Symptoms:Usually kidneys and liver are
affected;belly swells and foul smelling
yellowish fluid is found in visceral cavity.
Treatment:no cure

6.  (c)Infectious pancreatic necrosis(IPN):It is a
contagious disease of salmonids and
confined to North America.
 The virus affects mainly young trouts.
 Symptoms:affected fish revolves;swims
disorderly and finally rests at the bottom and
body cavity filled with a white fluid.
 Treatment:no cure;bury or burn the infected
fish

7.  2.Bacterial diseases:The bacterial diseases may
be;
 (a)Dropsy:It a serious epidemic
diseases,caused primarily by a becterium
Aeromonas punctata.
 Symptoms: Accumulation of yellow or pink liquid
in the body cavity. Fins are partly distroyed.
Belly swells and fish look like a baloon
 Treatment: dip treatment in 5 ppm potassium
permenganate solution is recommended.

8.  (b)ulcer disease:this disease is common at
brook trout hatcheries in USA.
 It is caused by a bacterium Hemophilus piscium.
 Symptoms:formation of open sores of
ulcers:lesions appear as a small pimple;fin rays
fall out.
 Treatment:chloromycetin is recommended as an
effective control.copper sulphate treatment is
also effective.

9.  (c)vibriosis:it is common in estuaries and marine
envoirnment.it is caused by Vibrio angullarium.
 These infections have been reported in
freshwater salmonids recently in Norway.
 Symptoms:dull movements,loss of
appetite,necrosis of kidney and bleeding at the
base of fins.
 Treatment:oxytetracycline at a ratio of 50-70
mg/kg of body wt/day for 10 days is
recommended.sufla drugs are also effective.

10.  3:Fugal disease:these may be;
 (a)Branchiomycosis:popularly known as ‘’gill rot
disease”.It is caused by a genus Branchiomyces.
 This disease mainly occurs in hot weather.it is
associated with rich organic matter such as dung,and
bloom of planktonic algae.
 Symptoms:In late stages of the disease gill filaments
decay and finally drop off;affected fish succumbs
from suffocation.
 Treatment :bath treatment into 3-5% salt solution or in
5ppm of potassium permenganate sol recmnded.

11.  (b)Icthyophonus disease:It is caused by
Icthyophonus hoferi, a brownish yellow fungi.
 It attacks the internal organs of fish.
 Symptoms: fish loses equilibrium, mouth
becomes open and rigid, tubling movements;
death may take few months to many years.
 Treatment:no cure.

12.  4.Trematodes:it includes ;
 (a)clinostomiasis:these infects a wide variety
of freshwater fishes and cause a disease
called as ‘yellow grub’.
 Symptoms: small sized cream colored
nodules are produced on body , head and
fins; infecion does not cause serious
disease.
 Treatment: no cure.

13.  Non infectious diseases: these may be;
 (a).Anoxia: Mortality of fish due to anoxia is
frequent problem in ponds of tropical countries.
 5 ppm is considered as sufficient concentration.
 Conc less than 3 ppm may prove to be fatal.
 Possible measures:(1).fresh water should be
added to the ponds.
 (2).thining of population of fish,removal of algal
blooms.

14. .(b)PH concentration: If ph goes below causes
acidemia.
. normal range of ph is from 7-8.
.Due to this disease fish perform rapid
movements and a tendency to jump out of
water.
.treatment:powdered calcium carbide can
reduce this problem.

15.  (c):Intoxications : heavy metals such as
zn,cu,Hg,Ni and Pb can enter into a pond or
lake from industries.
 If water is hard with a ph of 8 so heavy
metals ppts.
 But if water is soft with low ph,the metals in
their ionic forms will prove toxic to fishes.