The largest of all known extant fish species, the endangered whale shark reaches lengths of over 12.5 metres. Apart from their huge size, they are distinguished by their dark grey skin, patterned with linear rows of white spots. They have incongruously
small eyes, and wide, flat heads. Whale sharks are found in all tropical and warm-temperate seas, and are harmless to humans despite their large size. They are filter-feeders, living almost exclusively on plankton, with juvenile whale sharks eating approximately 21 kilograms of plankton every day. Whale sharks are ovoviviparous, meaning that they produce eggs which hatch internally before being born live. It’s thought that they are capable of storing sperm and fertilising their eggs in batches over a long period of time.