How much do whale sharks eat?

How much whale sharks eat depends on their size. As a general rule, whale sharks eat between 0.5 % and 3% of their body weight at each meal. They have a slow metabolism which means they need two to three days to digest their meal. So, if a fully grown whale shark weighs about 13 tonnes, it might eat almost 400 kilograms of food every 2-3 days. The whale shark feeds by filtering huge amounts of plankton and tiny sea creatures through its gills as it swims. It swims with its mouth open, sucking in huge amounts of water filled with small animals and plankton. This water is then filtered through spongy tissue around its gills. After the whale shark closes its mouth, it uses gills rakers, which are thousands of bristles around 10cm long in its mouth, to filter and eat the tiny plants and animals, which can include small fish, crustaceans and squid. A whale shark will often swim into schools of tiny creatures so as to maximise how much it can trap in its mouth. Because of the way it feeds, and the facts that its 3000 tiny teeth are virtually useless, a whale shark presents no danger to people.