Water quality, cyanobacteria, and disease were studied in four commercial shrimp (Penaeus vannamei) ponds and six fiberglass tanks over a two-month period. High temperatures, decreased water exchange and increased applications of fertilizers encouraged algal blooms containing Oscillatoria lutea, Spirulina subsalsa, Schizothrix calcicola, and Microcoleus lyngbyaceus, filamentous cyanobacteria previously linked to hemocytic enteritis (HE), a nutritional disease. Gut contents from tank-raised postlarvae, and pond-raised juveniles contained cyanobacteria identified as Microcoleus lyngbyaceus, Schizothrix calcicola, and Oscillatoria lutea. Histopathology examination of eighty-one postlarvae and juvenile Penaeus vannamei showed no signs of HE. Evidence suggests juveniles and early adults cultured in ponds containing cyanobacteria may have been infected with vibriosis (a disease caused by gram-negative bacteria). Tank-raised postlarvae exhibited "runt deformity syndrome" (RDS), a disease linked to infectious hypodermal and hematopoietic necrosis virus (IHHNV).
| Date of Award | Jan 1 1992 |
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| Original language | English |
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| Supervisor | Bart J. Baca (Supervisor), Curtis Burney (Advisor) & Charles Messing (Advisor) |
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