To vannamei or not to vannamei … … that is the question

Marine Cage Culture Sites Movement of shrimps between countries within a species’ range is okey. Borders between countries are political … Shrimps don’t know that.

Marine Cage Culture Sites Movement of fish outside its biological barrier is debatable! All Quarantine new arrivals … it could save the others!

A hypothetical “exotic shrimp transfer network”

Motive for species introduction: When a native organism is not suitable for aquaculture When culture of the native stock crashes

Consequences of Movement when a species is introduced, it is not just individuals of that organism that travel … parasites and diseases that the organisms suffer from travel as well Problems arise when the exotic organisms escape from culture facilities either in the form of adults or larvae. Native species may be more susceptible to the exotic disease These exotic species can interbreed or out compete the native species and destroy the natural stocks.

Disease and diagnosis Decreased production Sub-clinical disease Clinical disease When disease is present, only a small part of the population usually shows clinical disease Carriers

Knowing a Pathogen is Costly d istribution (how contagious it is) duration of infection (will it kill the whole stock?) survival time outside the host (does it incubate or hide somewhere?) ability to multiply and remain viable in water environmental fate number of infectious units required to cause infections and pathogenicity host specificity to determine if cross species infections or disease are likely to occur development of immunity

Disease avoidance approaches No introduction Inspection at source Inspection upon entry Quarantine Introduction of stock known to be clean Biosecurity is a problem!

The tiger is our own! Why lose it?