Rosamma, Philip; Kumar, S; Achuthankutty, C T(2006)
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Abstract:
Aquaculture farms, particularly in Southeast Asia are
facing severe crisis due to increasing incidences of
White Spot Syndrome Virus (WSSV). Actinomycetes
have provided many important bioactive compounds of high prophylactic and therapeutic value and are
continually being screened for new compounds. In this
communication, the results of a study made to determine
the effectiveness of marine actinomycetes against the white spot disease in penaeid shrimps are presented.
Twenty-five isolates of actinomycetes were tested for
their ability to reduce infection due to WSSV among
cultured shrimps. When these actinomycetes were
made available as feed additives to the post-larvae of
the black tiger shrimp Penaeus monodon for two weeks and challenged with WSSV, the post challenge survival
showed variations from 11 to 83%. However, six
isolates have shown to be the most potential candidates
for further study.
Hatha, A A M; Mujeeb Rahiman, K M; Deborah, Gnana Selvam(The ScientificWorld Journal, October 31, 2011)
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Abstract:
A yearlong (September 2009–August 2010) study was undertaken to find out possible reasons for occasional occurrence of
White Spot Syndrome Virus (WSSV) outbreak in the traditional prawn farms adjoining Cochin backwaters. Physicochemical and
bacteriological parameters of water and sediment from feeder canal and four shrimp farms were monitored on a fortnightly basis.
The physicochemical parameters showed variation during the two production cycles and between the farms studied. Dissolved
oxygen (DO) content of water fromfeeder canal showed low oxygen levels (as low as 0.8mg/L) throughout the study period. There
was no disease outbreak in the perennial ponds. Poor water exchange coupled with nutrient loading from adjacent houses resulted
in phytoplankton bloom in shallow seasonal ponds which led to hypoxic conditions in early morning and supersaturation of DO
in the afternoon besides considerably high alkaline pH. Ammonia levels were found to be very high in these ponds.WSSV outbreak
was encountered twice during the study leading to mass mortalities in the seasonal ponds. The hypoxia and high ammonia content
in water and abrupt fluctuations in temperature, salinity and pH might lead to considerable stress in the shrimps triggeringWSSV
infection in these traditional ponds
Description:
The ScientificWorld Journal
Volume 2012, Article ID 340830, 11 pages