Fin Whale (Balaenoptera physalus) is the second-largest animal on Earth and a fast, streamlined member of the Baleen whales. It lives in every major ocean, from polar feeding grounds to subtropical and temperate waters, and is notable for its speed, size, and distinctive asymmetrical jaw coloration.
Adults commonly reach 18–22 m (59–72 ft) in length, with the largest females recorded around 26 m (85 ft). Their combination of length, hydrodynamic body shape, and powerful tail strokes allows bursts up to about 37 km/h (23 mph), earning the species its “greyhound” nickname.
Fin whales belong to the rorqual group (family Balaenopteridae), which includes several of the world’s lunge-feeding giants. They are closely related to the Blue whale and smaller rorquals such as the Minke whale, sharing throat pleats that expand during feeding.
Fin whales typically weigh about 40–70 metric tons (44–77 short tons), with large individuals sometimes exceeding 80 tons. Body length is usually 18–22 m, and the tall, falcate dorsal fin sits far back on the body—an identifying feature at sea.
Their coloration is dark gray to brownish-black above and lighter below, with a hallmark asymmetry: the lower right jaw is often pale or white while the left is darker. Like other rorquals, fin whales have 50–100+ throat grooves (ventral pleats) that expand to take in massive mouthfuls of water during feeding.
Fin whales have a near-cosmopolitan range, occurring in the North Atlantic, North Pacific, Southern Ocean, and many offshore regions of the Indian Ocean. They favor deep, productive waters along continental slopes, oceanic fronts, and upwelling zones where prey concentrates.
Many populations show seasonal movement patterns, feeding at higher latitudes in summer and shifting toward lower latitudes in winter—an example of large-scale Marine mammal migration. They are often seen singly or in small, loose groups, though temporary feeding aggregations can form where prey is abundant.
Fin whales are gulp-feeders that strain prey through baleen plates instead of teeth. Their diet varies by region but commonly includes Krill and small schooling fish such as herring, capelin, sand lance, and anchovy.
During a lunge, a fin whale accelerates into a dense prey patch, opens its mouth, and engulfs a volume of water that can exceed the whale’s own body volume. It then closes its jaws and forces water out through the baleen, trapping prey on bristly fringes before swallowing.
Behaviorally, fin whales can be quieter and less surface-active than some other rorquals, but they are famous for long-distance, low-frequency calls that can travel tens to hundreds of kilometers in favorable conditions. In the wild they typically live about 70–90 years, while confirmed lifespans in captivity are rare because fin whales are not maintained in captive facilities.
The fin whale is listed as Endangered on the IUCN Red List (2018), reflecting historic population collapses and ongoing pressures. Global abundance is commonly estimated at roughly 100,000 individuals (often cited around 75,000–120,000), though figures vary by ocean basin and survey method.
The greatest historic threat was industrial Whaling, which removed hundreds of thousands of fin whales during the 20th century. Commercial whaling moratoria and management under the International Whaling Commission helped many populations begin to rebound, though recovery is uneven and slow for a long-lived species.
Modern threats include ship strikes, entanglement in fishing gear, underwater noise, and climate-driven shifts in prey distribution. Conservation efforts focus on enforcing whaling bans where applicable, reducing vessel collision risk in key corridors, and improving monitoring through acoustic surveys and photo-identification.