cultured shrimp are getting affected by various disease.some of them are acute and some chronic. and the curing is very harder for a farmer so it is better suggested for safety precaution and proper hygiene while culturing.and the affected shrimp in cured with antibiotics is not accepted by anyone in the export business. so, let yourself find out the various shrimp disease their cure and proper management in this seminar.
1. “Important Shrimp Diseases in India”
West Bengal university of animal and fishery sciences
A Seminar on
Submitted to:
Dr. G. Dash
Dept. of AAH
Submitted by:
Shiva Rajak
Roll No.- FS-27/14
AAH- 312
4. Introduction
Cultured shrimps suffer from various diseases due to infectious and non-infectious
causes.
Infectious diseases are caused by viruses, bacteria, fungi and certain parasites.
Non Infectious diseases are mainly are caused by adverse environmental
conditions, nutritional disorders, or genetic defects.
Treatment cannot be carried out effectively when shrimp diseases occur in a
pond.
The best way to get rid of diseases is by practicing good farm management or
prevention.
In this regard, information on various kinds of diseases and their prevention
procedures are useful.
5. Infectious disease
Infectious disease are due to hostility of bacteria, fungi, virus,
protozoa and Protista. These pathogen cause severe effects
in the health and appearance of the shrimp hence,
deteriorating their quality.
7. MONODON BACULOVIRUS DISEASE
ETIOLOGICAL AGENT
MBV-type or PmSNPV is a type A occluded monodon baculovirus
CLINICAL SIGNS
Lethargy, anorexia, poor feeding, dark colouration and reduced growth rate. Infected shrimps
are often associated with fouling of gills and appendages by ciliates such as Zoothamnium spp.
and Vorticella spp. Acute infection leads to loss of epithelial cells of hepatopancreas.
TREATMENT OR PREVENTION
No treatment yet but there is little information on prevention and control of the MBV infection in
shrimp pond culture. The prevention method for the mbv infection is possibly through avoidance
by screening the pl's before stocking shrimp in the pond
8. HEPATOPANCREATIC PARVO-LIKE VIRUS (HPV)
DISEASE
ETIOLOGICAL AGENT
CLINICAL SIGNS
TREATMENT
PREVENTION AND CONTROL
HPV is caused by a small parvo-like virus, 22-24 nm in diameter
No information is available on the prevention and control procedures for HPV infection. However, screening the
PLs before stocking shrimp by routine histology or the Giemsa-impression smear method is recommended.
Reduced feeding, poor growth rate, body surface and gill fouling
with ciliates and occassional opacity of abdominal muscles.
Severe infections may include a whitish and atrophied
hepatopancrease, anorexia and reduced preening activity. Losses
may be occur due to the increased occurance of surface and gill
fouling organisms and secondary infections by the
opportunistic Vibrio spp.
No treatment available for HPV
infection
9. YELLOW HEAD DISEASE
ETIOLOGIC
AL AGENT
TREATMEN
T
CLINICAL
SIGNS
PREVENTI
ON &
CONTROL
YELLOW HEAD VIRUS is a ssrRNA , rod
shaped, enveloped virus with two
rounded ends.
The affected shrimp shows a marked reduction
in food consumption.
Following this, a few moribund shrimp will
appear swimming slowly near the surface of the
pond dike and remain motionless.
The animals have pale bodies, a swollen
cephalothorax with a light yellow to yellowish
hepatopancreas and gills. A high mortality rate
may reach 100% of affected populations within
3-5 days from the onset of disease
No treatment is available for YHV
infection.
The reliable method to prevent the occurrence of
YHD is possibly through avoidance, such as careful
selection of post larvae, reduction or elimination of
horizontal transmission including carriers,
disinfection of contaminated ponds or equipment
with 30 ppm; and chlorine, providing shrimp with
good waterquality and proper nutrition
10. INFECTIOUS HEPATOPANCREAS AND LYMPHOID
ORGAN NECROSIS (IHLN)
ETIOLOGICAL AGENT
The primary cause of the disease is
attributed to viral etiology.
CLINICAL SIGNS
• Light pinkish to yellowish discolouration of the cephalothorax region.
• Often fouling by ciliate protozoan Zoothamnium seen.
• Blackened and necrotic hepatopancreas.
• Secondary bacterial infection from bacteria such as Vibrio
alginolyticus seen.
TREATMENT
PREVENTION AND CONTROL
No treatment is available for IHLN
infection.
• Keep the physico-chemical condition of
pond environment within acceptable
levels.
• To avoid bacterial and viral pathogen
entering from outside, closed culture could
be useful in prevention of IHLN disease.
11. WHITE SPOT
DISEASE
Etiological Agent
The disease is caused by the dsDNA virus, Systemic
Ectodermal and Mesodernal Baculovirus (SEMBV).
Clinical Signs: Clinically affected shrimp were first seen
to swim to the water surface and congregate at the pond
dikes. Typical clinical signs include white spots or
patches, 1-2 mm in diameter, on the inside of the shell
and carapace, accompanied by reddish discoloration of
the body. SEMBV is able to cause acute epizootics of 5-
10 days duration with mortality rate from 40% to 100%.
Treatment
No treatment is available for SEMBV infection.
Diagnosis Procedure The diagnosis procedure of SEMBV
infection is based on the appearance of the intranuclear
hypertrophy in stained histological sections and the presence of
virus particles in the nucleus of the infected cells observed under
the electron microscope. PCR technique is recently used to
detect SEMBV in shrimp larval and other stages, including
broodstock and subclinical virus carriers.
Prevention and Control Prevention practices through
avoidance are strongly recommended for the farmers, involving
the combinations of efficient pond management, use of proper
feed, selection of good quality of PL, reduction of possible
carriers, avoidance of introduction of contaminated water into the
13. LUMINOUS
VIBRIOSIS
ETIOLOGIC
AL AGENT
TREATMEN
T
CLINICAL
SIGNS
PREVENTI
ON &
CONTROL
Vibrio harveyi,
Vibrio vulnificus
High mortality rate in young juvenile
shrimp (one month syndrome).
Moribund shrimp hypoxic often come
to the pond surface and edges of
pond.
Vertical swimming behavior
immediately before onset of acute
mortality. Presence of luminescent
shrimp in ponds.
Disinfection of intake water with
Formalin (100-200 ppm).
Administration of Oxolinic acid (0.6
ppm) and Sarafloxacin (5mg/kg)
through feed for 5 days.
Proper pond and water
management. Utilization of
reservoir for intake water.
14. VIBRIOSIS
Vibrio vulnificus, V. parahemolyticus, V. alginolyticus, V.
anguillarum, V. damsella, V. fluvialis and V. mimicus.
High mortality rates, particularly in young juvenile shrimp.
Moribund shrimp with corkscrew swimming behavior appear at
edge of pond. Reddish discoloration of juvenile shrimp.
Black spots, chronic soft shelling.
Disinfection of intake water i.e. formalin 100-200 ppm. Anti-
microbial preparation application through feeds (Oxolinic acid
0.6 ppm and Sarafloxacin 5 mg/kg).
Proper pond and water management and utilization of reservoir
for intake wate
ETIOLOGICAL AGENT
PREVENTION &
CONTROL
CLINICAL SIGNS
EXTERNAL FOULING
TREATMENT
16. CLINICAL SIGNS Eggs and larve are weak and appear whitish. Moratlities may
reach 100% within two days. Fungal mycelium replaces the
larval tissues and ramifies into all parts of the body and
protrudes out of the body and develops into sporangia.
LARVAL MYCOSIS
PREVENTION &
CONTROL
General hatchery management practices such as use of UV sterilised and
filtered seawater, adequate water exchange etc., must be strictly followed.
Rearing water, equipment used in the hatchery and all hatchery facilities
must be thoroughly disinfected before retarting the hatchery operations.
ETIOLOGICAL
AGENT
Filamentous fungi of
genus Lagenidium spp. and other
filamentous fungi, such
as Sirolpidium spp. and Haliphthoros spp.
17. BLACK GILL DISEASE
ETIOLOGICAL
AGENT
Fusarium sp.
CLINICAL SIGNS
Brownish to blackish
discoloration on the gills
of juvenile shrimp.
TREATMENT
No treatment is available
for fungal infestation
without harming the
shrimp.
PREVENTION &
CONTROLNo information on prevention and
control. However, good management
of the pond bottom and prevention of
the entry of wild crustaceans into the
pond, which may carry pathogen,
can be effective control practices.
19. SURFACE
FOULING
DISEASES
Etiological Agent
Many species of bacteria, algae and protozoa such as filamentous
bacteria, Leucouthrix sp., Flavobacterium sp. and Zoothamnium sp.
Clinical Signs
Infected shrimps show black/ brown gills or appendage discoloration or
fuzzy/cottony appearance due to a heavy colony of the organisms. In some
cases, the severely affected shrimp die during the molting period.
Treatment
Chlorine and formalin are often used to treat those commensal organisms if
shrimp display heavy infection. Changing water is the most preferable
management, which stimulates molting of the shrimp in order to reduce the
infestation.
Prevention and Control
Prevention and control of the occurrence of surface fouling are usually done
through maintenance of good sanitary conditions at the pond bottom and the
overall pond area. Organic matters and suspended solids in the pond should be
reduced to prevent the attachment of those fouling organisms. This is achieved
by changing the water or applying lime.
20. MICROSPORIDOSIS (COTTON
SHRIMP DISEASE OR MILK SHRIMP
DISEASE)
Microsporidia such
as Thelohania spp., Nosema s
pp., and Pleistophora spp.
ETIOLOGICAL
AGENTS
Infected shrimps appear opaque
and cooked.
Gradual and low levels of
mortalities are observed.
Microsporidia invade and replace
gill, muscle, heart, gonads and
hepatopancreas, and cause
necrosis in these regions.
CLINICAL SIGNS
Maintain of good sanitary
conditions at the pond bottom and
the overall pond area.
PREVENTION AND
CONTROL
22. MUSCLE NECROSIS
MMuscle necrosis in shrimp is caused by
temperature and salinity shock, low
oxygen levels, overcrowding, rough
handling and severe gill fouling.
MUSCLE NECROSIS
There is a gradual death of cells of affected
parts leading to erosion especially
in the tail. This may then serve as portal of
entry for secondary systemic bacterial
infection.
EFFECT ON HOST
Affected shrimp show opaque white areas
on the abdomen blackening
on the edges of the uropod followed by
erosion and liquid-filled boils at the
tip of uropods in advanced stages; “wood
grain” appearance of abdominal
muscle in postlarvae
SIGNS
Reduce stocking density and improve
water quality by daily water change
(5-10%)
PREVENTION
E
S P
23. BENT/CRAMPED TAILS OR BODY
CRAMP
1
DISEASE
Bent/cramped tails or body cramp in shrimps is associated
with handling of shrimp in warm, humid air much warmer than
culture water, and mineral imbalance.
3
EFFECT ON HOST
Partially cramped shrimps swim with a humped
abdomen; fully cramped shrimps lie on their sides at the
pond/tank bottom. Healthy shrimps may cannibalize
weak ones.
2
SIGNS
Affected shrimps have partial or complete rigid
flexure of the tail
4
PREVENTION AND
CONTROL
Avoid possible causes.
24. INCOMPLETE MOLTING
ETIOLOGICAL AGENT
Incomplete molting is closely associated with
low temperature of culture water.
EFFECT ON HOST
• Abnormal swimming movement which could lead
to easy predation and mortality.
SIGNS
Presence of old exoskeleton attached to
newly molted larvae, especially in
appendages
PREVENTION AND CONTROL
• Maintain optimum temperature in the
rearing water
• Use water heater
25. RED DISEASE
ETIOLOGIC
AL AGENT
CLINICAL
SIGNS
EFFECT ON
HOST
PREVENTI
ON &
CONTROL
Red disease in shrimps is
associated with high application of
lime (2-6 tons/ha) in the pond that
gives it a high initial pH; prolonged
exposure to low salinity (6-15 ppt).
Yellow to red discoloration in affected
shrimps; histopathology of the
hepatopancreas shows hemocytic
infiltration in the spaces between the
tubules; more advanced lesions are in
the form of fibriotic and melanised
encapsulation of necrotic tissues,
either in the tubule itself or the sinuses
around it.
Affected shrimps have red short
streaks on gills or abdominal
segments, yellowish to reddish
discoloration of the body and
increased fluid in the
cephalothorax, emitting foul odour.
Prepare pond bottom properly
Reduce lime and organic matter
content inputs
26. SOFT SHELL
SYNDROME
Etiological Agent
The exact cause of soft-shell syndrome is not known.
However, low saline condition in the culture pond and
deterioration of pond bottom condition are some
physico-chemical factors that causes this disease.
Shrimps fed with low protein diet, contamination through
agricultural run-off, high soil pH, low water phosphate
and low organic matter in soil all have an impact on soft-
shell disease.
Clinical Signs
Shrimps are weak, usually off-feed, have a loose thin
exoskeleton. Rostrum is stiff as healthy shrimps. Wavy
undulating intestine is clearly visible.
Prevention and Control
Low stocking density, feeding with high quality feed and
frequent water exchange are likely to reduce the
recurrence of the disease.
27. 1. Shrimp being the high value food both in its nutritional and export value.
2. There are infectious and non-infectious disease affecting the health of the shrimp.
3. The best way to cure a disease is by better prevention methods and good farm management
practices.
4. Viral disease of shrimp leads to huge loss of production because it has got no treatment.
5. Bacterial disease is less harmful than that of virus and can be controlled by antibacterial
treatment.
6. The pathogen take over host only if the pathogen is getting enough optimum environmental
condition for it successful multiplication.
7. Disease occurs in shrimp either by primary or by secondary infection.
8. Shrimp treated with antibiotics are generally discarded if exported as food outside country so
it is better to take prevention measures rather than treatment.
9. It can be better prevented by selection of SPF(specific pathogen free) or SPR(specific
pathogen resistance) stocks of seeds before stocking.
10.Non-infectious disease can be treated by maintaining appropriate stocking density and giving
proper diet with complete nutrition in case of nutritional disease and maintaining appropriate
optimum conditions.
28. 28
1. HANDBOOK OF FISHERIES AND AQUACULTURE
2. http://www.celkau.in/Fisheries/CultureFisheries/Shrimps/dismagt.aspx
3. https://repository.seafdec.org.ph/bitstream/handle/10862/729/Erazo-PagadorG2001-
Environmental-and-other-non-infectious-diseases.pdf?sequence=1&isAllowed=y
4. web.oie.int/eng/normes/fmanual/2.2.00_INTRO_CRUSTACEANS.pdf
5. www.oie.int/.../Home/.../HepatopancreaticParvovirusCard2007_Revised92707_.pdf
6. CLASS NOTES OF DR. GADADHAR DASH “PRAWN DISEASE-CAUSES, DIAGNOSIS,
PREVENTION AND TREATMENTS.”
7. http://www.slideshare.net/SittoVietnam1/disease-and-management-for-shrimp-culture
8. http://www.slideshare.net/SittoVietnam1/disease-by-viral-pathogen
