Susceptibility to Taura Syndrome Virus of Some Penaeid Shrimp Species Native to the Gulf of Mexico and the Southeastern United States
Experimental studies demonstrated that Penaeus setiferus, but not Penaeus aztecus or Penaeus duorarum, could be killed by Taura syndrome virus (TSV). However, specimens of P. setiferus that survived infection and both P. aztecus and P. duorarum at least 79 days postexposure that did not demonstrate gross signs of infection were shown to harbor virus by bioassay using Penaeus vannamei, a highly susceptible target host. Consequently, all three of those penaeids native to the southeast United States can serve as carriers or reservoir hosts of TSV without necessarily exhibiting disease. Infections in P. setiferus took longer to cause mortality than in P. vannamei and killed a smaller percentage of that host. Also, histological lesions diagnostic of TSV infection were not always evident in sectioned tissue of infected P. setiferus, and they generally were more conspicuous during Days 4-7 postexposure compared with lesions that also occurred at both earlier and later days in tissues of P. vannamei. Infections could be produced by injection, ingestion, and incorporation of the infective material into dietary brine shrimp. There appeared to be a difference in susceptibility to TSV disease by different stocks of P. setiferus, but different experiments produced conflicting evidence regarding a relationship between age and predilection to mortality. Large and small specimens of equal-aged shrimp succumbed similarly to TSV infections for both P. vannamei and P. setiferus. The nonnative species P. chinensis demonstrated a high susceptibility to experimental TSV disease.
Overstreet
RM
Gulf Coast Research Laboratory, Institute of Marine Sciences, Ocean Springs, Mississippi, 39566-7000
Lightner
DV
Hasson
KW
McIlwain
S
Lotz
JM