Abstract:
Large numbers of adult Nile crocodiles, Crocodylus
niloticus (Laurenti), died from pansteatitis during
autumn and winter 2008 in the lower Letaba and
Olifants River gorge in the Kruger National Park,
South Africa. Consequently, the health status of
fish from these waters was investigated. The study
presents the pathological findings in fish inhabiting
these rivers within the boundaries of the Park.
Changes typical of steatitis were diagnosed in
many of the larger specimens of sharptooth catfish,
Clarias gariepinus (Burchell), caught within the
Olifants River gorge. These fish carried large
amounts of mesenteric fat with characteristic small
brown granulomata within the adipose tissue.
Necrosis and inflammation of the adipose tissues,
with characteristic ceroid accumulation within the
resultant granulomata and the associated aggregation
of ceroid-containing macrophages, were
demonstrated histologically and were typical of
steatitis. Other changes included mild thickening
and pallor of the gill tissues and swollen, orange,
fatty livers. Focal hepatic lipidosis was demonstrated
histologically, and special stains revealed
storage of large amounts of iron in the livers.
Blood smears revealed chromatin clumping in
erythrocyte nuclei and nuclear and cell membrane
irregularities. This is the first record of steatitis in
wild-caught C. gariepinus.
