Branchiomycosis in fish by deepak

Branchiomycosis is a fungal disease in mostly fresh water fishes.

1. BRANCHIOMYCOSISBRANCHIOMYCOSIS
(GILL ROT)(GILL ROT)
Guided by:- Dr. Guided by:- Dr.
Goverdhan sirGoverdhan sir
Submitted by:- Submitted by:-
Deepak singh Deepak singh
naruka (B.V.Sc. & naruka (B.V.Sc. &
A.H. 3A.H. 3
rdrd
year) year)

2. Definition:Definition:
It is a fungal disease involving gill tissues, It is a fungal disease involving gill tissues,
affecting the most species of freshwater affecting the most species of freshwater
fish. The disease is caused fish. The disease is caused
by by Branchiomyces Branchiomyces
sanguinissanguinis and and Branchiomyces demigransBranchiomyces demigrans. .
It is characterized by areas of infarctive It is characterized by areas of infarctive
necrosis of the gills, anorexia, and necrosis of the gills, anorexia, and
marbling appearance of the gills.marbling appearance of the gills.

3.  Branchiomycosis Branchiomycosis
of fish: A - of fish: A -
branching hyphae branching hyphae
of the fungus of the fungus
Branchiomyces Branchiomyces
sanguinissanguinis
 B - fungus hyphae B - fungus hyphae
spreading in the spreading in the
branchial blood branchial blood
circulation, ... circulation, ...
..

4. Causative agent:Causative agent:
There are two species from genus Branchiomyes, which are There are two species from genus Branchiomyes, which are
responsible for occurrence of the disease.responsible for occurrence of the disease.

1.1. B. sanguinisB. sanguinis: It grows mainly in the blood vessels of : It grows mainly in the blood vessels of
gill arches, filaments and in the gill lamellae.gill arches, filaments and in the gill lamellae.
2.2. B. demigransB. demigrans: This fungal species is found in the : This fungal species is found in the
parenchymal tissues of the gills.parenchymal tissues of the gills.
Both species produce branched and non-septate hyphae. Both species produce branched and non-septate hyphae.
The fungi grow at temperature between 14 and 35C. The The fungi grow at temperature between 14 and 35C. The
optimun growth temperature appears to be between 25 optimun growth temperature appears to be between 25
and 32C. The fungi grow on Sabouraud's dextrose agar and 32C. The fungi grow on Sabouraud's dextrose agar
medium.medium.

5. Stress factors:Stress factors:
1.1. Elevation of the water Elevation of the water
temperature above 20C.temperature above 20C.
2.2. Low dissolved oxygen. Low dissolved oxygen.
3.3. Reduced water flow. Reduced water flow.
4.4. Over crowded conditions. Over crowded conditions.
5.5. High levels of nutrients in the High levels of nutrients in the
water and phytoplankton blooms.water and phytoplankton blooms.

6. Susceptible species:Susceptible species:
The most species of freshwater The most species of freshwater
fishes are susceptible to fishes are susceptible to
branchiomycosis.branchiomycosis.

Mode of transmission:
Fungal spores are transmitted by water to gills. These
spores adhere to the gills, germinate and produce
hyphae.
The hyphae penetrate gills epithelium or within the
blood vessels of gills depending on species of fungi.

7. Incubation period:Incubation period:
Incubation period for disease is related to water Incubation period for disease is related to water
temperature. The disease has been rapidly developed within temperature. The disease has been rapidly developed within
2-4 days under suitable conditions.2-4 days under suitable conditions.

Clinical signs:Clinical signs:
1.1. Fish become weak in movement. Fish become weak in movement.
2.2. Fish are gathered in groups at water inlet and die. Fish are gathered in groups at water inlet and die.
3.3. Fish do not react to the approach of man and can be Fish do not react to the approach of man and can be
caught by hand.caught by hand.
4.4. There are respiratory distress in infected fish and do There are respiratory distress in infected fish and do
not swallow the air.not swallow the air.
5.5. Fungus develops on or in gill tissue, or penetrates the Fungus develops on or in gill tissue, or penetrates the
blood vessels causing obstruction, congestion and necrosis blood vessels causing obstruction, congestion and necrosis
of gill tissues.of gill tissues.
6.6. Gills may be appearing red from impaired circulation. Gills may be appearing red from impaired circulation.
7.7. Subacute form of branchiomycosis characterized by Subacute form of branchiomycosis characterized by
marbling appearance of the gills due to pale anemic patches marbling appearance of the gills due to pale anemic patches
in contact with red congested one due to disturbance of in contact with red congested one due to disturbance of
circulation in gills.circulation in gills.

8. Carp with branchiomycosis (gill Carp with branchiomycosis (gill
mycosis )mycosis )

9. B.sanguinisB.sanguinis in fish in fish

10. Diagnosis:Diagnosis:
1.1. Case history. Case history.
2.2. Clinical signs. Clinical signs.
3.3. Microscopical examination of Microscopical examination of
wet preparation from infected gill.wet preparation from infected gill.
4.4. Isolation and identification of Isolation and identification of
the causative agent.the causative agent.
  

11. Prognosis:Prognosis:
Morbidity rate among fish Morbidity rate among fish
populations with epizootics of populations with epizootics of
brachiomycosis usually reach 100% brachiomycosis usually reach 100%
depending on fish species and depending on fish species and
susceptibility. Mortality rate may susceptibility. Mortality rate may
each 30 to 50% of the fish each 30 to 50% of the fish
population during late summer population during late summer
epizootics.epizootics.

12. Treatment and control:Treatment and control:
1.1. Strict sanitation and disinfection are essential for Strict sanitation and disinfection are essential for
disease control.disease control.
2.2. Dead fishes should be collected and daily and burned Dead fishes should be collected and daily and burned
or deeply buried.or deeply buried.
3.3. Ponds with enzootic branchiomycosis should be dried Ponds with enzootic branchiomycosis should be dried
and treated with calcium oxide (quicklime) or 2 to 3 kg and treated with calcium oxide (quicklime) or 2 to 3 kg
copper sulphate per hectare.copper sulphate per hectare.
4.4. Diseased fish can be treated with malachite green at Diseased fish can be treated with malachite green at
0.1mg/l for extended periods of time or 0.3mg/l for 12 0.1mg/l for extended periods of time or 0.3mg/l for 12
hours.hours.
5.5. Transportation of infected fish areas to non-infected Transportation of infected fish areas to non-infected
areas must be prevents.areas must be prevents.
6.6. Increase of water supply help in control of that Increase of water supply help in control of that
disease.disease.
7.7. Stress factors must be avoided. Stress factors must be avoided.
8.8. Regulating the feeding rate during warm weather. Regulating the feeding rate during warm weather.