SUSCEPTIBILITY TO TAURA SYNDROME VIRUS OF SOME PENAEID SHRIMP SPECIESNATIVE TO THE GULF-OF-MEXICO AND THE SOUTHEASTERN UNITED-STATES

Experimental studies demonstrated that Penaeus setiferus, but not Pena eus aztecus or Penaeus duorarum, could be killed by Taura syndrome vir us (TSV). However, specimens of P. setiferus that survived infection a nd both P. aztecus and P. duorarum at least 79 days postexposure that did not demonstrate gross signs of infection were shown to harbor viru s by bioassay using Penaeus vannamei, a highly susceptible target host . Consequently, all three of those penaeids native to the southeast Un ited States can serve as carriers or reservoir hosts of TSV without ne cessarily exhibiting disease. Infections in P. setiferus took longer t o cause mortality than in P. vannamei and killed a smaller percentage of that host. Also, histological lesions diagnostic of TSV infection w ere not always evident in sectioned tissue of infected P. setiferus, a nd they generally were more conspicuous during Days 4-7 postexposure c ompared 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 b rine shrimp. There appeared to be a difference in susceptibility to TS V disease by different stocks of P. setiferus, but different experimen ts 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 su sceptibility to experimental TSV disease. (C) 1997 Academic Press.