Rosamma, Philip; Annies, Joseph(Elsevier, August 25, 2007)
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Abstract:
Influence of acute salinity stress on the immunological and physiological response of Penaeus monodon to white spot
syndrome virus (WSSV) infection was analysed. P. monodon maintained at 15‰ were subjected to acute salinity changes to 0‰
and 35‰ in 7 h and then challenged orally with WSSV. Immune variables viz., total haemocyte count, phenol oxidase activity
(PO), nitroblue tetrazolium salt (NBT) reduction, alkaline phosphatase activity (ALP), acid phosphatase activity (ACP) and
metabolic variables viz., total protein, total carbohydrates, total free amino acids (TFAA), total lipids, glucose and cholesterol were
determined soon after salinity change and on post challenge days 2 (PCD2) and 5 (PCD5). Acute salinity change induced an
increase in metabolic variables in shrimps at 35‰ except TFAA. Immune variables reduced significantly (Pb0.05) in shrimps
subjected to salinity stress with the exception of ALP and PO at 35‰ and the reduction was found to be more at 0‰. Better
performance of metabolic and immune variables in general could be observed in shrimps maintained at 15‰ that showed
significantly higher post challenge survival following infection compared to those under salinity stress. Stress was found to be
higher in shrimps subjected to salinity change to lower level (0‰) than to higher level (35‰) as being evidenced by the better
immune response and survival at 35‰. THC (Pb0.001), ALP (Pb0.01) and PO (Pb0.05) that together explained a greater
percentage of variability in survival rate, could be proposed as the most potential health indicators in shrimp haemolymph. It can be
concluded from the study that acute salinity stress induces alterations in the haemolymph metabolic and immune variables of
P. monodon affecting the immunocompetence and increasing susceptibility to WSSV, particularly at low salinity stress conditions
Rosamma, Philip; Bright Singh, I S; Sudheer, N S(Elsevier, November 23, 2010)
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Abstract:
The objective of the study was to find out a natural way to fight white spot syndrome virus (WSSV) in cultured
shrimps, as the present scenario necessitated an organic remedy for the devastating pathogen in crustaceans.
Under this research programme seven mangrove plants were collected, identified and aqueous extracts
screened for their protective effect on the giant tiger shrimp Penaeus monodon against WSSV. The
experimental design consisted two modes of application, such as exposure of the virus to the extract and
injection challenge, and oral administration of the extract coated feed followed by oral challenge. All
experimental animals were monitored through a nested diagnostic PCR analysis. Of the seven mangrove
extracts screened aqueous extract from Ceriops tagal imparted total protection to shrimp from WSSV when
challenged by both methods. Shrimps administered with the aqueous extract from C. tagal were devoid of
virions. The HPLC fingerprint of the aqueous extracts from C. tagal showed more than 25 peaks and 7 of them
were larger and well separated. Preliminary phytochemical analysis revealed the presence of alkaloids,
flavonoids, polyphenolics, cardiac glycosides, saponins and sterols. The study indicated suitability of the
aqueous extract of C. tagal as a possible prophylaxis for WSSV infection in shrimp. This is the first report on the
anti WSSV property of the mangrove plant C. tagal