--- title: "Bobbit Worm (Eunice aphroditois) | AnimalTracks.wiki" description: "An ambush predator up to ten feet long that buries itself in the sand with its jaws cocked like a spring trap, ready to snap a passing fish in half." image: "https://animaltracks.wiki/images/animals/bobbit-worm-1.webp" published: "2026-08-31" updated: "2026-09-17" --- # Bobbit Worm (*Eunice aphroditois*) > **Status**: Checked against 5 sources, listed under Sources below. > **Tagline**: An ambush predator up to ten feet long that buries itself in the sand with its jaws cocked like a spring trap, ready to snap a passing fish in half. > **Soundtrack Vibe**: Nu-Metal & 90s Alt-Metal // Deftones, "My Own Summer (Shove It)" > **Soundtrack Links**: [Spotify](https://open.spotify.com/track/1158ckiB5S4cpsdYHDB9IF) | [YouTube](https://www.youtube.com/watch?v=XOzs1FehYOA) > **Vibe Match**: It lies buried in its burrow with its jaws "under tension like an armed spring trap," then snatches a fish and is gone in about a tenth of a second: the same quiet-to-detonation swing as a song built on hushed verses that explode into heavy, aggressive hits. ## Biological Superpowers & Stats - **Taxonomy**: *Eunice aphroditois* - **Danger Level**: High - **Conservation Status**: Not Evaluated ([IUCN Red List](https://www.iucnredlist.org/)) - **Superpower**: An eversible pharynx tipped with sharp maxillae that thrusts out of its burrow fast enough to split a passing fish in half, with five antennae and two eyes to detect prey. - **Habitat**: Buried in sediment on the sea floor of warm waters across the Indo-Pacific and Atlantic. - **Diet**: Fish, bivalves, and other segmented worms. - **Tags**: invertebrate, benthic, carnivore, ambush-predator, burrower ## Natural History & Behavior ## Buried Alive, Waiting A bobbit worm lives out of sight, in a mucus-lined burrow in rocks or sediment. *Eunice aphroditois* can grow up to three meters long, about ten feet, on a body up to two centimeters across, and it stays buried in the loose seabed with five striped antennae poking out of the sand. The largest one recorded measured 299 centimeters and weighed 433 grams, and it may be the longest polychaete, a bristly marine worm, on record. These worms live in the sedimentary beds of warmer oceans, including the Indo-Pacific and the Atlantic. A bobbit worm is not blind: it has two eyes on the front of its head. Researchers think its five antennae help lure and detect prey, and that it detects a meal mainly by sight and touch. By day it waits for something to brush an antenna. At night it changes tactics and actively hunts, poking out of its burrow to snatch passing prey. ## The Bite When a fish drifts close, the worm's jaws sit "under tension like an armed spring trap." It rapidly thrusts out an eversible pharynx, a throat that turns inside out to strike, tipped with sharp maxillae, its jaw pincers, grabbing prey and sometimes splitting a fish in half. In the attacks researchers filmed, the whole ambush, from snatch to the worm vanishing back underground, took about a tenth of a second. Whatever it catches also gets injected with a toxin that helps digest the meal. Bobbit worms are known to bite humans and can cause severe wounds. > **Fish Fight Back** A fish called *Scolopsis affinis*, which feeds near the seabed, turns on its hunter: when one spots a hidden bobbit worm, it blasts jets of water into the burrow, and others often join in. Researchers diving in Indonesia filmed 46 of these water-jet attacks. In 16 of them, the worm reacted by pulling in an antenna or retreating completely into its burrow. ## An Old Trick Ambush burrowing like this is not new. In Taiwan, scientists described a fossil burrow up to two meters long, L-shaped, with distinct feather-like structures around its upper shaft. Compared with the burrows of living animals, its shape strongly suggests ambush-predatory worms that lived about 20 million years ago. Further back still, 400-million-year-old rocks in Canada preserve fossil jaws over a centimeter long from *Websteroprion armstrongi*, an extinct bristle worm with a body estimated at more than a meter long. Giant, heavily jawed worms are not a recent invention, even if that ancient one's feeding habits remain unclear. ## Frequently Asked Questions ### How large can a bobbit worm actually get? The largest one recorded measured 299 centimeters, just under ten feet, and weighed 433 grams, which may make it the longest polychaete, or bristle worm, on record. The worm stays buried in the loose seabed, with five striped antennae protruding from the burrow to lure prey fish. *(Source: [Lachat & Haag-Wackernagel 2016]())* ### How does a bobbit worm catch a fish? When a fish drifts close, it rapidly thrusts out an eversible pharynx, a throat that turns inside out to strike, tipped with sharp maxillae, its jaw pincers, and grabs the fish. The still living animal is then dragged down into the burrow to be eaten. *(Source: [Pan et al. 2021]())* ### Does a bobbit worm really have no eyes? No. It actually has two eyes on its head, in addition to its five antennae. Researchers think the antennae help lure and detect prey, and that the worm detects a meal mainly by sight and touch. *(Source: [Lachat & Haag-Wackernagel 2016]())* ### Can a bobbit worm really reach six meters? There are published claims of individuals in the genus Eunice reaching 6 meters, but some authors have argued that they are rather in the order of 3 meters. Eunice aphroditois, the bobbit worm, is the largest species known in that genus. *(Source: [Eriksson, Parry & Rudkin 2017]())* ## Sources 1. [The Bobbit Worm. Smithsonian Ocean, Smithsonian Institution.]() 2. [Lachat & Haag-Wackernagel (2016). Novel mobbing strategies of a fish population against a sessile annelid predator. Scientific Reports.]() 3. [Pan et al. (2021). The 20-million-year old lair of an ambush-predatory worm preserved in northeast Taiwan. Scientific Reports.]() 4. [Shinomiya et al. (2023). Molecular and Morphological Assessment of Juvenile and Adult Forms in the Giant Worm Eunice Cf. Aphroditois (Annelida: Eunicidae) and Its Phylogenetic Position in the Family. Zoological Science.]() 5. [Eriksson, Parry & Rudkin (2017). Earth’s oldest ‘Bobbit worm’ – gigantism in a Devonian eunicidan polychaete. Scientific Reports.]() *Published August 31, 2026. 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