Which endangered shark is the largest living fish species?

The whale shark is the largest living fish species. Despite its name and whale-like size, it is a shark—a cartilaginous fish—not a mammal. Its scientific name is Rhincodon typus, and it is the only living member of its family, Rhincodontidae.

Whale sharks are filter feeders. They strain plankton, krill, fish eggs, and small schooling fish from seawater through specialized gill structures. This diet helps explain why the species is generally docile around divers, unlike the predatory great white shark.

The whale shark is also the largest living non-cetacean animal. Basking sharks and megamouth sharks are other large filter-feeding sharks, but neither reaches the whale shark’s maximum size. The species was formally described in 1828 after a specimen was harpooned near Table Bay, South Africa.

Whale sharks migrate through tropical and warm-temperate oceans, often gathering seasonally where plankton is abundant. Fishing, accidental capture, ship strikes, and habitat pressures have contributed to major population declines, and the IUCN lists the species as Endangered.