An adult black sea bass (Centropristis striata) was presented with
abdominal distension and decreased appetite. A large firm abdominal swelling was evident on
examination. Differentials for this abdominal mass included neoplasia, abscess/granuloma,
hematoma, normal gonad hyperplasia, or swimbladder abnormality. Diagnostics included survey
radiography, positive-contrast radiography, and computed tomography. A barium enema was
performed and radiographs indicated unhindered passage of contrast throughout the
gastrointestinal tract. A gonadal tumor was suspected based on diagnostic findings. The sea bass
was anesthetized with tricaine methanesulfonate. Water with anesthetic was pumped through tubing
placed in the fish's oral cavity. The fish was placed in dorsal recumbency and passively secured
in place by the slightly V-trough surgical table. A ventral midline abdominal incision revealed
the descending intestines closely adhered to the irregular, tan-pink, red and brown, bulging
abdominal mass. Adhesions to the mass were gently dissected both sharply and bluntly.
Post-operatively, the fish recovered uneventfully in the holding tank. Radiographs were repeated
eight weeks post-operatively, which showed no evidence of mass regrowth at this time.
Radiography and computed tomography have been previously reported diagnostic
modalities used in fish, but to the authors' knowledge, this is the first report of a barium
enema being performed diagnostically in fish. While surgical procedures are performed more
commonly on fish in the research arena, few reports of clinical surgical cases have been
described. This case supports conclusions found in previous reports that certain surgical
procedures can be performed safely in fish.