Gulf Sturgeon (Acipenser oxyrhynchus desotoi) are a threatened anadromous fish species indigenous to Florida's Suwannee River. Brood stock are collected in the wild and spawned in captivity by the University of Florida and the National Fisheries Research Center. Fingerlings are raised as part of a stock enhancement program for release.

Fish were spawned in March, 1992. The fingerlings (approximately 2,000) were fed a diet of live brine shrimp until June when the food source was changed to black worms (Lumbriculus variegatus). Five days later fish began dying and within 3 days, 95% of the population died. External examination showed that moribund fish were thin with hemorrhage into the dorsal, caudal, anal, pelvic fins and the ventrolateral aspect of the body. Gills and skin were not remarkable. Internal necropsy on the moribund animals showed white, friable livers with petechia throughout; spleens were pale and enlarged; kidneys were pale. There was a moderate amount of clear fluid in the intestines. Cultures were taken from the posterior kidney and liver, then streaked on 5% ovine blood agar. In 24 hours a pure culture of Streptococcus sp. grew in all fish. Surviving animals were treated with Erythromycin at 100 mg/kg of body weight daily PO. Source of the infection was traced to their food source, black worms (Lumbriculus variegatus). The culture of black worms was discontinued, and brine shrimp substituted as a food source for the young fish. The survivors of the epizootic are still in captivity and appear normal.