Photo Fiona Sunquist ©
Sharks differ from other fish in that their skeletons are made of cartilage not bone. In contrast to bony fish, which have a single gill cover, sharks have five or more gill slits on each side of the head.
The fossil record shows that sharks that differ very little from the sharks we see today, were swimming in the earth’s oceans more than 400 million years ago, making them older than the dinosaurs.
Most sharks are carnivorous, feeding on fish, sea mammals, crabs, and worms. However a few are plankton feeders– the massive, 60-foot long whale shark, the basking shark and the “mega mouth” are plankton feeders.
Three hundred and seventy five species of sharks have currently been described, and more than 50 of these species can be found in the waters around Florida. Many of these species are deep-water or bottom dwelling creatures, rarely seen by the average Floridian.
top of page | back to sharks
|