Diseases of fish

Fish Diseases

1. Topic: DiseasesofFish
Dr. RamkumarLodhi
Conservation Biology Lab

2. synopsis
Introduction.
Dropsy.
Tail Rot or Fin Rot.
Eye diseases.
Furunculoris.
Costiasis.
White spot (Itch).
Fungal diseases.
Swimming bladder diseases.
Conclusion.
Reference.

3. INTRODUCTION
Large no of diseases occurs in all aquatic animals including fish.Dueto
nutritional deficiency or unhygienic condition of water or attack of
parasites.
All species of fishes becomes infested with pathogenic bacteria.
A sick fish generally is unable to maintain balance in the water,usually
lie on the side either at the bottom are floating at the surface.
The gills becomes pale,bodycovered with grey slime and there is
normal colour.
A sick fish is sluggish skinnessof the fish in the pond may be due to
the change in the physico–chemical of water and due to shortage of
food.

4. DROPSY
In this diseases there is accumulation of fluid in the internal
organs causing swellings.Intestine,liverand kidney are
badelyeffected.
It is caused by bacteria called psedomonaspuntataand
Aeromonas hydrophilla.
Most fishes with this problem can survive only 2-3 weeks
but sometimes as many months.
Dropsy is mainly found in carps like Catlaand Rohu.
Control measure
Dropsy is mainly treated with chloralphenicolantibiotics
added in water. The fishes kept in the solution for 3-7 days.
Food is not given to the fish during treatment

6. TAIL ROT OR FIN ROT
Tail rot is basically erosion and disintegration of fin and tail.
In earlier stage white line appears on fin which may leads to fin lost.
Tail rot is caused by Pseudomonas Floresence.
It occurs due to poor quality of water.
If fin rot is noticed in the early stages and treated then fish may be
survive. If tail rot remains untreated then entire tail is lost and fish
die.
Control measures
The diseases may be cured by dipping in the copper sulphate
solution for 1-2.
If heavy infection,theaffected portion of tail should be removed and
then wash by 1% silvarnitrate.
The fish kept in a diluted sol of potassium dichoromatefor healing of
wounds which may require 7-10 days

8. EYE DISEASE
This disease is caused by bacteria streptoccusiniae,as well
as Lactococcus,entrococ-cusrococcus.
The most common symptom of these bacteria will show as
cloudy eye and bulges outwards from eye cavity ,thus
called pop eye diseases.
The conorybecomes vascularised leading to opacity eye
becomes whitish and loss of balanacein the body of fish.
It is observed in Rohu catlaand silvarfish.
Control measures
The diseased fish may be treated by chloromycetin in the
early stage of this diseases,thenfish kept in 1% of KMnO4
for 3 minutes

10. FURUNCULOSIS
Mostly observed in salmon,troutand goldfish.
It is caused by bacteria Aeromonas salmonicida.
The infected fishdevelops swellings on the sides of the
body which may leads to ulcer.
The swelling contains pus like substance formed by
necrosis of muscle cells.
Control measure
Cured by antibiotics oxytetracycline and sulfamerazine.

12. This disease is caused by ectoparasite costiawhich is a flagellate that
attacks skin and gills, destroys epidermal cells and feed them.
As a result excessive secretion of mucus.
The body of the fish becomes covered with bluish or grey film of
mucus.
Loss of appetite, and becomes weak and dies after sometime.
Another protozoan ciliate chilodonalso attacks skin and gills.
Control Measures
Both the protozoan are controlled by treating the fish with 1% acetic
acid solution or solution of formalin.
Solutions of methylene blue, KMnO4, CuSO4 can also be used to kill
the parasite.
COSTIASIS

14. WHITE SPOT
ThisdiseasecausedbyciliatedprotozoanIchthyophthiriusspecies.
Theparasiteattackstheskinoffreshwaterfish,restinbetweenepidermisand
dermis.
Infectionresultsintheappearanceofseveralwhitespotsontheskin
andfinduetorapidproliferationofepidermalcells,whichformsacovering
overtheparasite.
Theentirebodyofthefisharecoveredbynodulestrophonts.
CONTROLMEASURES
Thefishkeptinthe3%saltsolutionor1%solutionofformalineandthen
methylene(2minutes).
Theparasitealsokilledbyrisingupthetemperatureabove24degreecelicious.

16. FUNGAL DISEASE
Thefungaldiseaseismainlycausedbyseprolegniaandare
characterisedbytheappearanceofwool(tufts)ontheskin.
Rootlikehyphaeorfilamentsgrowsintothesubcutaneousparts,
causingdeathofthefish.
Gillsarealsoaffectedcausinggillrot.Gillfirstbecomespalethenlatter
yellow-brownanddestroyed.
Theinfectionspreadquicklywhenthefishisalreadyinjuredand
weak.Healthyeggsalsoaffectedifdeadeggsarenotremovedfromthe
water.
CONTOLMEASURE
Thefishistakenoutfromthewaterandtheaffectedpartwashedwith
iodinesolution,thenthefishkeptunder1%potassiumdichromatefora
week.
Wecouldalsokeptthefishunder3%solutionofsaltaswellas1%
solutionofphenoxetholalsokillsthefungi.

18. SWIMBLADDERDISEASE
Swim bladder disease refers to a condition when the
swim bladder donotwork normally due to diseases
or environmental factors.
Affected fish will exhibit problems with buoyancy
that is ,they will have difficulty controlling their
ability to flout or sink.
Fish have swollen belly, mainly observed in gold fish.
Affected fish may eat normally or have no appetite at
all.Thisdisorder is some times caused by
compression of swim bladder,whichmay involve a
distended stomach from rapid eating or overeating
or gulping air.

19. CON….
Gestrointestinaltract enlargement puts pressure on the swim
bladder or other abdominal may enlarge and affect the swim
blader(kidney and liver)
Due to swim bladder disease, fishes don’t maintain normal
position in the water.
CONTROL MEASURE
If the fishes have SBD, the first course of action is not to feed
fish for three days.Atthe same increasing water
temperature(80 degree celicious).
Adding small amount of salt in the tank.Reducingthe water
level to make it easier for fish movement around the
tank.Handfeeding is necessary.

21. CONCLUSION
Thediseaseisharmfulforbothwildandcultured
fishesofourcountry.
Diseaseinfishesmaycauseaheavylossfor
commerciallyculturedfishes.Soweshouldbe
knowaboutthesignsandsymptomsofdisease,
thatwecaneasilyfindoutthepropertreatment.
Fisheriesisanimportanttoolofself-employment
becausefishisanimportantsourceofnutrients
andhavehavegreateconomicvalue.

22. REFERENCE
•S.S. KHANA and H R SING. Fish biology and
fisheries.
•Biology of fishs ;3
rd
edition by RICHARD
MOORE AND QUENTIN BONE.