One of the major disease problems in grow-out shrimp culture is the Luminous Vibriosis. .
Causative agent: Bacteria Vibrio harveyi, V. splendidus and other luminescent vibrios.
- Affects the eggs, larvae, post larvae and juveniles of the shrimp.
- Vibriosis weakens the larvae and juveniles. -Larvae become opaque-white while the juveniles have discolored portions on the body.
- As the common name of the disease suggests, the larvae glow green when in total darkness.
- Luminous Vibriosis can be deadly to the shrimp and has potential to kill up to 100% of the shrimp population.
- Mortalities due to vibriosis occur when shrimps are stressed by factors such as: poor water quality, crowding, high water temperature, low DO and low water exchange.
- Reddening of the body with red to brown gills, reduce feeding and may be observed swimming lethargically at the edges and surface of ponds.
- To prevent this, it is best to monitor the shrimp during their early stages and to check the bacteria present via water sample tests regularly.
- An increase in daily water exchanges and a reduction in pond biomass by partial harvesting are recommended to reduce mortalities caused by vibriosis.
- It is also advisable to create microbial diversity in the water to competitively exclude the pathogens by using probiotics.
Daily exchange of water which will help in reducing bacterial counts. PONDPRO and BIOCLEAN will reduce luminescent bacteria.