Shark Problems (from a human’s viewpoint) 181
V. damsela caused death in 18 hours. V. damsela can be transmitted to people,
causing gastroenteritis and septicemia (wound infection). A captive Epau-
lette Shark (Hemiscyllium ocellatum) was found to be infected with Mycobac-
terium avium, a bacterium that causes coughing, fever, diarrhea, and weight
loss in people. A dead Blacktip Reef Shark was found to be infected with
haemorrhagic septicaemia, caused by the bacterium Aeromonas salmonicida.
The bacterium caused inflamed lesions at the base of the fins and in the
gills, liver, and intestine. A. salmonicida infects a variety of fish, especially
salmon and trout, in which it is often fatal. Fortunately, it cannot be trans-
mitted to people.
Sharks are immune to most viruses with the exception of a herpes virus
found in wild and aquarium-kept Smooth Dogfish. This virus causes skin
lesions that grow with time. It is thought that immunity to most other vi-
ruses is aided by the chemical squalamine, which sharks produce in their
liver and other organs. Lab tests have shown that squalamine inhibits the
replication of at least six different viruses, including those responsible for
dengue fever, hepatitis B and D, yellow fever, and a form of encephalitis.
Fortunately, squalamine can be produced synthetically and does not have
to be obtained from live sharks (see “Are any medicines made from sharks?”
in chapter 8).
One variation on the patented shark-
repelling wetsuit. The suit is deco-
rated with bold, contrasting stripes to
mimic the banding pattern of poison-
ous sea snakes. The varying angles of
the stripes are to account for different
swimming positions, because sea
snakes have vertical black and white
bands but a diver is not always lying
flat in the water. Used with permission of
N. Burkhead