Susceptibility to Taura Syndrome Virus of Some Penaeid Shrimp Species Native to the Gulf of Mexico and the Southeastern United States

Experimental studies demonstrated thatPenaeus setiferus,but notPenaeus aztecusorPenaeus duorarum,could be killed by Taura syndrome virus (TSV). However, specimens ofP. setiferusthat survived infection and bothP. aztecusandP. duorarumat least 79 days postexposure that did not demonstrate gross signs of infection were shown to harbor virus by bioassay usingPenaeus 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 inP. setiferustook longer to cause mortality than inP. vannameiand killed a smaller percentage of that host. Also, histological lesions diagnostic of TSV infection were not always evident in sectioned tissue of infectedP. 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 ofP. 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 ofP. 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 bothP. vannameiandP. setiferus.The nonnative speciesP. chinensisdemonstrated a high susceptibility to experimental TSV disease.