The Whale Shark

For many divers, a whale shark sighting is analogous to finding diving’s Holy Grail. Over the years, untold numbers of divers have made countless excursions in pursuit of their dream dive. Fortunately, in recent years the diving community has discovered several places where whale sharks reliably aggregate and where water conditions are generally good during certain times of year.

FAMILY

Rhincodontidae. Like the basking shark, the whale shark is the only species in its family.

GENUS AND SPECIES

Rhincodon typus

DESCRIPTION

The common name whale shark is an obvious reference to the enormous size of whale sharks. Numerous sources list the maximum length as being approximately 42 feet with a common adult length being closer to 33 feet. The maximum reported weight is 34 tons. Size alone makes it rather easy to identify whale sharks. The body is generally streamlined and somewhat flattened with the head being even more flattened. Whale sharks have a wide, flattened mouth located the front of the face (terminal position). Other features include small eyes compared to the overall body size, large gill slits, a tall first dorsal fin that is significantly larger than the second, numerous whitish spots on the top and upper sides of the body, and a semi-lunate tail with the upper lobe being larger than the lower lobe.

While the body color of whale sharks varies, they are generally dark brown to grayish to dark blue or black. The underbelly is off-white.

When actively feeding, whale sharks swim mouth agape. The size of the cavernous mouth is staggering, and a sighting creates one of the more memorable moments that a diver can ever experience.