---
title: "What the sources say about the Bobbit Worm | AnimalTracks.wiki"
description: "41 claims from the Bobbit Worm profile, each beside the words of the source that backs it."
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canonical: "https://animaltracks.wiki/animals/bobbit-worm/sources/"
---

# What the sources say about the Bobbit Worm (*Eunice aphroditois*)

> 41 claims from the Bobbit Worm profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Bobbit Worm](https://animaltracks.wiki/animals/bobbit-worm/)

## The Bobbit Worm. Smithsonian Ocean, Smithsonian Institution.

https://web.archive.org/web/20250217005538id_/https://ocean.si.edu/ocean-life/invertebrates/bobbit-worm

| The page says | The source says |
| :--- | :--- |
| about ten feet | up to ten feet long |
| sometimes splitting a fish in half | sometimes splitting its fishy prey in half with its sharp teeth |
| Whatever it catches also gets injected with a toxin that helps digest the meal | It also injects them with a toxin to help break down its food to make it easier to digest. |

## Lachat & Haag-Wackernagel (2016). Novel mobbing strategies of a fish population against a sessile annelid predator. Scientific Reports.

https://doi.org/10.1038/srep33187

| The page says | The source says |
| :--- | :--- |
| A bobbit worm lives out of sight, in a mucus-lined burrow in rocks or sediment. | Bobbits reside in mucus-lined borrows in rocks or sediments. (note: Framing sentence for the paragraph; the burrow itself is the quoted claim.) |
| it stays buried in the loose seabed with five striped antennae poking out of the sand | During the day, Bobbits are buried in the loose seabed waiting for a stimulus on one of their five antennae that protrude from the hidden burrow to lure prey fish (note: "Striped" from the same source: "five striped antennae that exhibit wormlike movement".) |
| The largest one recorded measured 299 centimeters and weighed 433 grams, and it may be the longest polychaete, a bristly marine worm, on record | The largest specimen of a recorded Bobbit worm was 299 cm long, weighing 433 g, and it may be the longest of the polychaete worms |
| These worms live in the sedimentary beds of warmer oceans, including the Indo-Pacific and the Atlantic. | The Bobbit worm lives in the sedimentary beds of warmer oceans, including the Indo-Pacific and Atlantic |
| it has two eyes on the front of its head | Bobbits have two eyes on the prostomium (note: The prostomium is the head lobe at the front of the worm.) |
| Researchers think its five antennae help lure and detect prey | five striped antennae that exhibit wormlike movement and presumably serve to lure and detect prey |
| it detects a meal mainly by sight and touch | Bobbits appear to detect their prey mainly by visual and tactile cues. |
| By day it waits for something to brush an antenna | During the day, Bobbits are buried in the loose seabed waiting for a stimulus on one of their five antennae that protrude from the hidden burrow to lure prey fish |
| At night it changes tactics and actively hunts, poking out of its burrow to snatch passing prey | At night, the Bobbit changes its strategy and actively hunts by protruding from its burrow and snatching passing prey. |
| the worm's jaws sit "under tension like an armed spring trap" | the jaws are under tension like an armed spring trap |
| the whole ambush, from snatch to the worm vanishing back underground, took about a tenth of a second | The entire process from the snatching of a prey until complete disappearance lasted approximately 0.1 s. (note: Measured across the filmed predation events in the mobbing study, not a species-wide claim; the sentence says "In the attacks researchers filmed".) |
| Bobbit worms are known to bite humans and can cause severe wounds. | Bobbits are known to bite humans and can cause severe wounds. |
| 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 | The fish direct sharp water jets towards the hidden sessile annelid predator Eunice aphroditois (Bobbit worm) (note: S. affinis is "a common demersal species that lives and feeds near the seabed of the western Pacific". Joining: "S. affinis individuals either mob alone or form mobbing groups.") |
| 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 | During the remaining 46 observations, S. affinis directed water jets at the Bobbit ... in 16 observations (34.8%), the Bobbit showed a visible reaction by retracting an antenna or completely retracting into its burrow. (note: Dive site named in Methods: Air Prang, Lembeh Strait, Sulawesi, Indonesia.) |
| 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. | the jaws are under tension like an armed spring trap (note: "Up to ten feet" is the smithsonian claim above; "snap a passing fish in half" is the smithsonian splitting claim above.) |
| 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 jaws are under tension like an armed spring trap (note: The tenth of a second is the same 0.1 s claim above: snatch to complete disappearance, not the strike alone.) |
| 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 largest specimen of a recorded Bobbit worm was 299 cm long, weighing 433 g, and it may be the longest of the polychaete worms (note: "Just under ten feet" is 299 cm converted.) |
| The worm stays buried in the loose seabed, with five striped antennae protruding from the burrow to lure prey fish | During the day, Bobbits are buried in the loose seabed waiting for a stimulus on one of their five antennae that protrude from the hidden burrow to lure prey fish |
| No. It actually has two eyes on its head, in addition to its five antennae | Bobbits have two eyes on the prostomium |
| Researchers think the antennae help lure and detect prey, and that the worm detects a meal mainly by sight and touch. | five striped antennae that exhibit wormlike movement and presumably serve to lure and detect prey (note: "Detects a meal mainly by sight and touch" is the same visual/tactile cues claim above.) |
| Buried in sediment on the sea floor of warm waters across the Indo-Pacific and Atlantic. | The Bobbit worm lives in the sedimentary beds of warmer oceans, including the Indo-Pacific and Atlantic |
| Not Evaluated | the hidden sessile annelid predator Eunice aphroditois (Bobbit worm) (note: stats.conservationStatus. No reference in the profile states a Red List status; this quote anchors the species name only. GBIF's copy of the Red List returns NOT_EVALUATED for Eunice aphroditois (Pallas, 1788), usage key 5198482 (https://api.gbif.org/v1/species/5198482/iucnRedListCategory), checked 2026-09-17, and source:prefetch found no Crossref assessment DOI under this name (2026-09-15). The house convention for an unassessed species is to carry no status reference (#596).) |
| tags: invertebrate | the hidden sessile annelid predator Eunice aphroditois (Bobbit worm) (note: Replaces the `mammal` tag (#596). Eunice aphroditois is an annelid, a polychaete worm, so it has no backbone: the tag reads "Animals lacking a backbone or spinal column". The same paper calls it "the longest of the polychaete worms".) |
| tags: benthic | The Bobbit worm lives in the sedimentary beds of warmer oceans (note: Replaces the `coral-reef` tag (#596), whose definition is navigating "complex limestone reef structures". The tag reads "Living on the bottom of aquatic bodies, crawling over sediments, rocky reefs, and seabed deposits", and the same paper adds "Bobbits reside in mucus-lined borrows in rocks or sediments".) |

## Pan et al. (2021). The 20-million-year old lair of an ambush-predatory worm preserved in northeast Taiwan. Scientific Reports.

https://doi.org/10.1038/s41598-020-79311-0

| The page says | The source says |
| :--- | :--- |
| on a body up to two centimeters across | Bobbit worms can grow up to 3 m long and 2 cm in diameter (note: The Smithsonian page says "a couple inches wide" (about 5 cm); Pan et al. give 2 cm, and the Pennichnus burrows are 2-3 cm in diameter, so the paper's figure is used.) |
| It rapidly thrusts out an eversible pharynx, a throat that turns inside out to strike, tipped with sharp maxillae | the Bobbit worm rapidly thrusts out of its burrow and grabs the prey with its eversible pharynx and sharp maxillae |
| scientists described a fossil burrow up to two meters long, L-shaped, with distinct feather-like structures around its upper shaft | This trace fossil consists of an up to 2 m long, 2–3 cm in diameter, L-shaped burrow with distinct feather-like structures around the upper shaft. (note: Pennichnus is a trace fossil, a burrow, not a body fossil.) |
| its shape strongly suggests ambush-predatory worms that lived about 20 million years ago | A comparison of Pennichnus to biological analogs strongly suggests that this new ichnogenus is associated with ambush-predatory worms that lived about 20 million years ago. (note: The paper's own verb is "strongly suggests", and it names no species: the sentence claims no more.) |
| Fish, bivalves, and other segmented worms. | They are ambush predators that feed on fish, bivalves, and other annelids |
| 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. | the Bobbit worm rapidly thrusts out of its burrow and grabs the prey with its eversible pharynx and sharp maxillae (note: Antennae/eyes covered by the novel-2016 claims above; splitting prey in half by the smithsonian claim above.) |
| 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 Bobbit worm rapidly thrusts out of its burrow and grabs the prey with its eversible pharynx and sharp maxillae |
| The still living animal is then dragged down into the burrow to be eaten. | The still living animal is then dragged down into the burrow for consumption |
| tags: ambush-predator | They are ambush predators that feed on fish, bivalves, and other annelids (note: Replaces the `super-bite-force` tag (#596): no source states a bite force, and an annelid has neither the "jaw adductor musculature" nor the "reinforced skull bones" that tag names. The same paper: "They hide in their burrows until they explode upwards grabbing unsuspecting prey with a snap of their powerful jaws".) |

## 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.

https://doi.org/10.2108/zs220075

| The page says | The source says |
| :--- | :--- |
| can grow up to three meters long | a large polychaete worm (up to 3 m in length) (note: The abstract states this length for Eunice aphroditois itself, before the paper turns to the separate Japanese Eunice cf. aphroditois form.) |

## Eriksson, Parry & Rudkin (2017). Earth’s oldest ‘Bobbit worm’ – gigantism in a Devonian eunicidan polychaete. Scientific Reports.

https://doi.org/10.1038/srep43061

| The page says | The source says |
| :--- | :--- |
| 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 | Websteroprion armstrongi was a raptorial feeder and possessed the largest jaws recorded in polychaetes from the fossil record, with maxillae reaching over one centimetre in length. Total body length of the species is estimated to have reached over one metre ... some 400 million years ago. (note: A Devonian eunicidan polychaete from Ontario, Canada: a fossil relative, not Eunice aphroditois.) |
| that ancient one's feeding habits remain unclear | more precise knowledge of the feeding habits of W. armstrongi remains elusive for the time being |
| 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. | there are published claims of individuals reaching 6 m in length ...; however, some authors have argued that they are rather in the order of 3 m (note: The dispute is about the genus Eunice generally, which the answer says.) |
| Eunice aphroditois, the bobbit worm, is the largest species known in that genus. | The largest species known is the famous ambush predator Eunice aphroditois (note: The same paper adds that the taxonomy of this species (or species complex) is controversial.) |