New Diseases of P. Monodon and L. Vannamei [Compatibility Mode]

8/2/2019 New Diseases of P. Monodon and L. Vannamei [Compatibility Mode]

1/17

Monodon Slow-Growth Syndrome


2/17

Growth Retardation Phenomenon in culturedP. monodon

Culture Period (d) 118 13

Water Salinity (ppt) 11 8

Average Body Weight (g) 12.5 3.4

Average Daily Growth (g/d) 0.11 0.03

Coefficient of Variation of Body Weights (%) 66 39


3/17

% of normal

size

shrimp

% of small

size

shrimpSingle infections 58 52MBV 38 30Microsporidian 13 6Gregarine 1 5HPV 0 2Bacteria 6 9

Dual infections 15 26MBV/HPV 7 10MBV/Microsporidian 7 6MBV/Gregarine 1 6HPV/Microsporidian 0 2Microsporidian/Gregarine 0 2Triple infections

9 7MBV/HPV/Microsporidian 7 5MBV/HPV/Gregarine 1 1MBV /Microsporidian/Gregarine 1 1

Quadruple infections 1 1Any of the tested pathogens 83 86None of the tested pathogens 17 15

Dual to quadruple infections 31 39Overall prevalence for each pathogen

MBV 63 60Microsproidians 29 23HPV 16 21Gregarines 5 16


4/17

Criteria for the GrowthRetardation Syndrome

Growth retardation, ADG < .at mo Size difference, CV >

Abnormal appearance

No significant MBV or HPV infections


5/17

Re-Infection Experiment Lymphoid organs of growth-retardedP. monodon from a commercial

farm

Lymphoid organ extract (LOE)

Homogenize (:with LHB)

Filtering through .mm

Stock healthyP. monodon ( - g BW, DOC< ) in l seawater

Tanks - = Control ( . ml LHB-injected)

Tanks - = . ml LOE injected

Determine BW, SR and general shrimp morphology at , and months


6/17

Decreasing Size of the LOE-Injected Shrimp

Buffer-injected

LOE-injected


7/17

Intense black-yellow stripes of LOE-injected shrimp

Buffer-injected

LOE-injected


8/17

Buffer-Injected

CV (%)

BW (g)

LOE-Injected

CV (%)

BW (g)


9/17

%SR

%CV

Buffer-injected LOE-injected


10/17

MSGV = YHV Type

MSGV = nm virus = Laemsingh Virus


11/17


12/17

)LHOG5HVXOWV VKRZHGWKDWRIWKHVORZJURZWKVKULPS

ZHUHYHZLWK573&5IRU


13/17

-nm new

virus found in

both normal and

small shrimp Two types of

new viruses

LaemsinghVirus

Tegumental

gland-associatevirus


14/17

Proportion and Growth Rateof Four Shrimp Families in a Common Pond

that Suffered from the Slow-Growth Phenomenon

.g/d.g/d .g/d.g/d

At Stocking At DOC At DOC

.g/d .g/d


15/17

MSGA

Grow slowly but

survive better

(survive but the

price the shrimp

have to pay is

-

Grow normally but

at low survival rate


16/17

Positive Results of RT PCR for Laemsingh Virus from the Field

Small-sized

shrimp

Normal-sized

shrimp

P. monodon From slow-growth pond(No. of ponds =

From normal

L. vannamei

.

of ponds =

M. rosenbergii From slow-growth pond(No. of ponds =

Later on, with more data, the

virus was found in mostP.

monodon, small or normal size

Laemsingh virus and tegumental gland-

associate virus are candidates for being

MSGS


17/17

Bamboo-ShapedL. vannamei

Documents

New Diseases of P. Monodon and L. Vannamei [Compatibility Mode]