Sharks

Updated 3/26/2023

Sharks

Many shark species occur in Hawai'i but few inhabit shallow reefs where they may be observed by divers with any regularity. They move through the water gracefully and are an impressive sight not easily forgotten. Encounters are usually brief as sharks are cautious and prefer to flee rather than be confronted by a large unfamiliar creature. They play an important role as apex predators that help maintain balance in marine ecosystems. Unfortunately sharks worldwide have been over-exploited and are much more difficult to find.

Sharks are primitive fishes with cartilaginous skeletons instead of bone. Most give birth to fully-developed young, few lay eggs on the seafloor. The jaws are lined with rows of developing teeth behind those in use for quick replacement. The tough leathery skin is protected by tiny scales called denticles with the same structure as teeth. Shark senses are bolstered by electro-reception, a system that detects electrical fields produced by animals. This system incorporates a network of gel-filled pits on the head called the ampullae of Lorenzini. Rays and skates are basically sharks with bodies designed for their role.

Contrary to popular belief, shark attacks are extremely rare and usually survivable. Most are the result of the animal mistaking a person as prey under conditions where positive identification is difficult. This risk is minimized by swimming slowly and calmly with a buddy in clear water during the day, and avoiding areas where prey congregate such as harbors and rivermouths.

HAWAII / CIRCUMTROPICAL

Carcharhinus galapagensis