Three Brown Sharks (Carcharhinus plumbeus) which had only recently arrived at the National Aquarium at Baltimore began to exhibit signs of disorientation.  The disorientation was followed by lethargy, and despite the use of antibiotics and other therapeutic measures, the animals died.  The most severely affected individual exhibited, in addition to central nervous system signs, large raised lesions which when opened yielded a brownish purulent exudate.  Internal necropsy examination revealed the presence of meningeal, renal, hepatic, rectal gland, and enteric lesions which were confirmed by histopathologic examination.  Specimens of cerebrospinal fluid, kidney, liver, spleen, and swabs from observed dermal lesions yielded two unique Vibrio species which will be discussed in a separate presentation.  Pure cultures of the two isolated Vibrios from one of the Brown Sharks (Diagnostic case #1116) were designated as 1116a and 1116b, respectively, and injected intra-abdominally into Spiney Dogfish (Squalus acanthius) as a solution of physiological saline (PSS) containing 4 x 10⁶ organisms per ml PSS.  The dose rate was 1.0 cc per individual.  Death occurred within 18 hours, and the organisms were recovered from specimens of kidney, liver, spleen, as well as swabs from the peritoneum and dermis.

This paper will discuss the clinical and necropsy findings of the three reports cases as well as results from reinfectivity studies which have been completed or are currently in progress.