Hawaiʻi Sharks

Incorrect. Sharks can see fairly well, if the water is clear. Some sharks are able to see colors.

Incorrect. Of the more than 380 species of sharks, only about 30 are believed to have been responsible for biting people. And only three (white, tiger, and bull) are considered particularly dangerous.

Incorrect. Although some sharks (like tigers) will feed on almost anything, including dead animals, all sharks are carnivores to some extent. Sharks that feed on plankton are eating small animals, including fishes.

Incorrect. People are not part of any shark’s natural diet. As with most sharks, tiger shark bites may often be cases of mistaken identity. Considering how many opportunities tiger sharks have to bite people, the low numbers of bites that actually occur suggest tiger sharks mostly avoid people.

Incorrect. Some sharks, especially demersal (bottom-dwelling) species, lay eggs by producing various forms of egg cases, but most sharks are live-bearing.

Incorrect. Shark skeletons are made entirely of cartilage, not bone.

Incorrect. Most sharks have to swim to force water over their gills. But many bottom-dwelling species have muscles in their pharynx (throat) that enable them to pump water over their gills while they’re not moving.

Incorrect. Shark teeth are attached to fibrous connective tissue, which is attached to the jaw. There is no direct attachment between the teeth and jaws.

Incorrect. Sharks are found in any kind of water, regardless of how clear or murky it might be.

Incorrect. Sharks are vulnerable in some areas, like the eyes, snout, and gills, and hitting a shark there may make it leave. On the other hand, it could make the shark more aggressive. Studies have shown that much more often than not, hitting a shark will have the desired effect, but it should be a last resort. Use an available object as a weapon if you can.

Incorrect. More people drown picking ‘opihi than are killed by sharks (fatal shark bites are extremely rare), so the ‘opihi might be considered Hawaii’s most dangerous sea creature.

Incorrect. Sorry, it’s a trick question. Although that’s true for most of the rest of the world, Hawaii has very few electrical storms and people are almost never hit by lightning. But you are more likely to be injured by a falling coconut than by a shark.

Incorrect. But the operative word is "may." Blood will certainly attract the attention of a shark. Other body fluids, such as urine or sweat, can probably be detected by sharks. But whether sharks find them "attractive" is unknown.

Incorrect. Most sharks take prey in an upright and level body position. The loose attachment of a shark’s jaws to its skull makes it possible for sharks to bite in any position.

Incorrect. Some sharks have brains that are larger than those of birds and mammals of similar sizes, and have been reported to learn at about the same rate as some birds and mammals. They have been trained to swim mazes and perform other tasks for food. The megamouth shark, on the other hand, has a very small brain (about half the size of an adult human thumb), so it’s hard to speculate on its capacity for learning.

Incorrect. Submarines and their towed arrays have been bitten many times by sharks, and so have various types of underwater cables. The sharks are probably attracted to electromagnetic fields, visual stimuli, or sounds produced by these objects.