How to recognise a whale shark?

Whale Sharks are not difficult to identify. For starters, they look like a really huge shark – measuring up to 20 meters long, and weighing as much as 30 metric tons. The other tell-tale sign is their distinctive markings. White spots in between vertical and horizontal white stripes creates a very attractive skin pattern, unique to each individual like a human finger print. A whale shark's head is broad and flat, with a very wide mouth up to 1.5 metres wide, and relatively small eyes just behind the mouth.

What is the origin of the strange name ‘Whale Shark’? Are they a whale, or are they a shark? Scientifically speaking they are classified as a shark species, but they do grow to sizes as large as a whale and eat plankton by filter-feeding similar to many whale species. So their name is rather fitting after all.

Galapagos whale shark behavior

In truth whale sharks are mysterious and enigmatic creatures, and little is known about their behavior and habits. At Galapagos, one of the great whale shark mysteries is why are 90% of the whale sharks found here pregnant females? Also why do most individuals visit just one specific site, Darwin Arch, and for such a short period of time? We don’t have all of the answers yet, but scientists are actively studying these fascinating creatures.

Very little is known about global whale shark breeding behavior, but the study of one female back in July 1996 did reveal some of their secrets. She was pregnant at the time with 300 pups in her belly, indicating that they are ovoviviparous – meaning that eggs hatch inside the female body before she gives birth. Baby whale shark pups measure from 40 – 60 cm when born, and grow very quickly – approximately 18 inches per year. They can live for up to 130 years, which explains in part how they become so large.

What do Galapagos whale sharks eat?

The principal whale shark diet consists of plankton, small fish, krill and fish eggs, eating up to 90 pounds each day. Galapagos whale sharks are filter feeders, sucking tons of water into their large mouths by swimming close to the surface with mouth wide open. This practice is known as ram-filter feeding. They filter through 350 rows of tiny teeth, and out again through their gills. If you are lucky enough to observe whale shark feeding at Galapagos then you are in for a real treat.