Giant oarfish stretch longer than any bony fish
Oarfish comprise three elongated pelagic species in the family Regalecidae, living from temperate seas into the tropics. The giant oarfish is the longest bony fish alive, reported near eight metres, and sick animals at the surface fed centuries of sea-serpent tales.
The family takes its name from the Latin for royal. There are three species in two genera: the giant oarfish, Russell's oarfish, whose largest known specimen measured 5.4 m, and the streamer fish, which tops out near 3 m. Their jelly-like flesh is poor eating, and although small commercial catches exist, live captures are rare. Beachings ahead of storms earned them a name as omens of disaster, a belief strengthened when many washed ashore before the 2011 Tōhoku earthquake and tsunami.
A single dorsal fin of roughly 400 rays begins above the large eyes and runs the whole body, its first ten or so rays lengthened into a red-spotted crest. There are no scales, no anal fin, no swim bladder and no true spines, and the body tapers to a point. New Zealand researchers even reported feeling electric shocks when they touched one. Many shed part of their tail to escape predators; every Russell's oarfish caught over 1.5 m had done so, and the tail never grows back. Heavily ossified bony rays along the back seem to brace the spine against stress fractures while swimming.
They live between about 250 and 1,000 m, where currents are weak, so they carry little muscle and usually die from pressure change if they drift up. In 2001 US Navy personnel inspecting a buoy in the Bahamas filmed one alive, rippling its dorsal fin while holding its body straight, and they are often seen hanging vertically, perhaps to spot prey outlined against the light above.
In 2008 a remotely operated vehicle filmed one in the Gulf of Mexico, estimated at five to ten metres; later sightings there reached nearly 500 m deep, and the fish reacted sluggishly to the machines, hinting at few predators. An angler landed a 3.3 m, 63.5 kg specimen at Skinningrove in England in 2003, and California logged only about twenty sightings between 1901 and 2024.
Source: Oarfish
