About
Sharks — cartilaginous fish of the class Chondrichthyes — have existed relatively unchanged for 450 million years (predating dinosaurs by 200 million years). There are approximately 500 species, ranging from the 17cm dwarf lanternshark to the 18m whale shark (filter feeder, harmless to humans). The great white shark (Carcharodon carcharias, up to 6m, 2,200 kg) is the largest predatory fish and the primary subject of shark mythology, fear, and the $470M Jaws franchise.
The reality vs. the myth: sharks kill fewer than 10 people annually worldwide; humans kill approximately 100 million sharks per year (primarily for shark fin soup — the industry removed an estimated 38% of sharks globally in a decade). Most shark attacks are cases of mistaken identity (surfers' profiles resemble seals from below). Sharks' electroreception (Ampullae of Lorenzini — gel-filled pores detecting electric fields down to 1 billionth of a volt, allowing navigation and prey detection) is among the most sensitive sensory systems in nature. The Greenland shark (Somniosus microcephalus) lives to 400+ years (oldest vertebrate), swimming at 1 km/h in Arctic waters and reaching sexual maturity at 150 years.
# Top 10 shark facts
- 1450 million years unchanged
- 2500 species
- 310 deaths/year by sharks vs. 100M sharks killed by humans
- 4great white 6m
- 5whale shark (18m, filter feeder)
- 6Greenland shark (400+ years, oldest vertebrate)
- 7ampullae of Lorenzini (electric field sensing)
- 8shark fin trade (38% decline in a decade)
- 9nurse shark (docile bottom-feeder)
- 10megalodon extinction
Fascinating Facts
- ◆The Greenland shark lives to 400+ years — making it the world's oldest known vertebrate — and reaches sexual maturity at approximately 150 years; it was only discovered to be this old in 2016 when researchers used radiocarbon dating of the eye lens (which retains proteins formed at birth) on sharks caught as bycatch
- ◆Humans kill approximately 100 million sharks per year — primarily for shark fin soup — while sharks kill fewer than 10 humans annually; this 10-million-to-1 ratio means a shark is 10 million times more likely to be killed by a human than a human is to be killed by a shark
- ◆Sharks can detect one drop of blood per 100 liters of seawater (roughly the size of a swimming pool), but their actual hunting behavior is based primarily on detecting struggling movements from injured fish — most shark 'attacks' on humans involve the shark biting once to investigate and then leaving when it realizes the human is not its normal prey
More in Animals4 related
8
Animals
Blue Whale
The largest animal that has ever lived on Earth — a living leviathan.
Interest90/100
71
Animals
African Elephant
The largest land animal on Earth — intelligent, empathetic, and endangered.
Interest78/100
74
Animals
Tiger
The largest wild cat — a solitary apex predator with one of the most iconic coats in nature.
Interest77/100
73
Animals
Lion
The king of the African savanna — the only social big cat.
Interest77/100