Overview

Brief Summary

Eunice aphroditois is a giant marine worm in the speciose polychaete family Eunicidae (which contains over 300 species names; Zanol et al. 2010; Fauchald 1992).  One of the world’s longest worms, E. aphroditois is a dramatic sight with different accounts measuring individuals 3-6 meters (10-20 feet) long, their bodies up to 25 mm (1 inch) across.  These omnivorous, opportunistic, free-living worms live head-up in burrows just under sand or gravel sediments or in boulders/coral rubble.  Five tentacles around their mouth, characteristic of the genus, extend in the water.  When it detects prey, the worm springs from its lair, everting its proboscis to expose a fierce pair of mandibles, with which it pulls the prey into its hole.  (Video here: https://www.youtube.com/watch?v=GAgWm3G44Aw&feature=player_embedded)

In the 1990s, a giant eunicid worm from the Indo-pacific was photographed and its astonishing feeding behavior documented (as Eunice sp., as even experts could not identify it to species) in an identification manual, Coral Reef Animals of the Indo-Pacific (Gosliner et al. 1996): “...with its 5 pairs of massive, spring loaded jaws, [this species] appears like a frightening apparition from a science fiction movie… This species is a voracious predator.  It was observed to feed on a file fish of more than 150 mm in length.  When the file fish ventured too close to the worm it emerged slightly from its burrow and seized the fish in its jaws with lightning speed.  In an instant, the worm had pulled the fish beneath the sand surface and begun to consume it.”

Originally described from tropical Indo-Pacific waters around Sri Lanka (Pallas 1788), this species is reported around the world, although experts believe this name confounds a multitude of similar-looking giant eunicid worm species.  For example, recent work formally distinguished the giant eunicid worm (and commercially important fishing bait species) that inhabits the Mediterranean and Agean Seas as E. roussaei rather than E. aphroditois (Zanol and Bettoso 2006).  The difficulties of teasing apart the different species morphologically has made taxonomy, systematics and understanding of the distribution and ecology of species within the genus Eunice very complex.  In combination with further study of type material and more collection at type locations, molecular bar coding and molecular phylogenetic characters may prove a helpful tool in the much needed task of defining this and other giant eunicid species more precisely (Schulze 2011; Salazar-Vallejo et al. 2011; Zanol et al 2010).

Gosliner et al. (1996) coined the name Bobbit worm for the Eunice sp. illustrated in their book, associating the worm to the at the time widely-discussed Lorena Bobbit court case.  The name simply refers to the sharpness of the worm’s mandibles slicing its prey under attack and the resemblance of the worm to a phallus when holding itself erect to catch prey, not to imply that this worm castrates its mate - which it doesn’t as these worms are broadcast spawners - however this misinterpretation has circulated especially on the web.  Just as most giant eunicid worms around the world are ascribed to the species name Eunice aphroditois, most of these worms are also referred to as the Bobbit worm, so rather than as a common name for E. aphroditois, “Bobbit worm” would be better applied generally to all giant eunicid worms (Mah 2013), although these giant worms are not necessarily a monophyletic grouping.

  • Fauchald, K. 1992. A review of the geus Eunice (Polychaeta: Eunicidae) based on type material. Smithsonian Contributions to Zoology, 523:422pp
  • Gosliner, T.M., D.W. Behrens and G.C. Williams 1996. Coral Reef Animals of the Indo-Pacific: Animal Life from Africa to Hawaii Exclusive of the Vertebrates. Sea Challengers. ISBN-10: 0930118219.
  • Mah, C. 17 September, 2013. Who Named the Bobbit Worm (Eunice sp.)? And WHAT species is it.. truly?? The Echinoblog. Retrieved June 5, 2015 from http://echinoblog.blogspot.com/2013/09/who-named-bobbit-worm-eunice-sp-and.html.
  • Salazar-Vallejo et al. 2011. Giant Eunicid Polychaetes (Annelida) in shallow tropical and temperate seas. Rev. Biol. Trop. 59-4: 1463-1474.
  • Schulze, 2011. The Bobbit worm dilemma: a case for DNA (Reply to Salazar-Vallejo et al.). Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 59 (4): 1475-1477,
  • Zanol J. and N. Bettoso, 2006. Identity of Eunice roussaei (Eunicidae: Polychaeta: Annelida) from the Adriatic and Mediterranean Seas. J. Mar. Biol. Ass. U.K. (2006), 86, 1017-1024.
  • Zanol, J., K.M. Halanych, T.H. Struck and K. Fauchald, 2010. Phylogeny of the bristle worm family Eunicidae (Eunicida, Annelida) and the phylogenetic utility of noncongruent 16S, COI and 18S in combined analyses. Molecular Phylogenetics and Evolution 55(2):660-676.
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Ecology

Habitat

Depth range based on 2 specimens in 1 taxon.
Water temperature and chemistry ranges based on 1 sample.

Environmental ranges
  Depth range (m): 95 - 25000
  Temperature range (°C): 10.915 - 10.915
  Nitrate (umol/L): 9.765 - 9.765
  Salinity (PPS): 34.731 - 34.731
  Oxygen (ml/l): 5.836 - 5.836
  Phosphate (umol/l): 0.638 - 0.638
  Silicate (umol/l): 3.242 - 3.242

Graphical representation

Depth range (m): 95 - 25000
 
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Known from seamounts and knolls
  • Stocks, K. 2009. Seamounts Online: an online information system for seamount biology. Version 2009-1. World Wide Web electronic publication.
translation missing: en.license_cc_by_4_0

© WoRMS Editorial Board

Source: World Register of Marine Species

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Depth range based on 2 specimens in 1 taxon.
Water temperature and chemistry ranges based on 1 sample.

Environmental ranges
  Depth range (m): 95 - 25000
  Temperature range (°C): 10.915 - 10.915
  Nitrate (umol/L): 9.765 - 9.765
  Salinity (PPS): 34.731 - 34.731
  Oxygen (ml/l): 5.836 - 5.836
  Phosphate (umol/l): 0.638 - 0.638
  Silicate (umol/l): 3.242 - 3.242

Graphical representation

Depth range (m): 95 - 25000
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

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Wikipedia

Eunice aphroditois

Eunice aphroditois (colloquially known as the Bobbit(t) worm), is an aquatic predatory polychaete worm dwelling at the ocean floor. This organism buries its long body into an ocean bed composed of gravel, mud, or corals, where it waits patiently for a stimulus to one of its five antennae, attacking when it senses prey. Armed with sharp teeth, it is known to attack with such speeds, its prey is sometimes sliced in half. Although the worm hunts for food, it is omnivorous.[1]

According to Luis F. Carrera-Parra and Sergio I. Salazar-Vallejo, ecologists specializing in annelid polychaetes at El Colegio de la Frontera Sur in Campeche, Mexico, eunicids inject "...[a] narcotizing or killing toxin in their prey animal, such that it can be safely ingested — especially if they are larger than the worm — and then digested through the gut".[2] They further state, unlike a different family of worms, the fireworms (Amphinomidae), which have harpoon-shaped chaetae (bristles) that release a toxin that can cause severe skin irritation, E. aphroditois specimens "do not have abundant chaetae and their chaetae are not used for defensive purposes, but for improving traction for crawling over the sediment or inside their galleries or tubes".[2]

Little is known about the sexual habits and lifespan of this worm, but researchers hypothesize that sexual reproduction occurs at an early stage, maybe even when the worm is about 100 mm (3.9 in) in length; this is very early, considering these worms can grow to sizes of nearly 3 m (9.8 ft) in some cases (although most observations point to a much lower average length of 1 m (3 ft 3 in) and an average of 25 mm (0.98 in) in diameter). A long lifespan may very well explain the size of these creatures.[verification needed]

E. aphroditois is found in warmer oceans around the world, including the Indo-Pacific and Atlantic.[3]

In aquaria[edit]

Bobbit worms may be accidentally introduced into artificial environments.[4] In March 2009, the Blue Reef Aquarium in Newquay, Cornwall, discovered a Bobbit worm in one of their tanks. The workers had seen the devastation caused by the worm, such as fish being injured or disappearing and coral being sliced in half, but did not find it until they started taking the display apart in the tank. The worm was nicknamed "Barry".[5]

Another Bobbit worm, three and a half feet long and a few inches thick, was found October 7, 2013 in Maidenhead Aquatics in Woking, Surrey.[6]

Name[edit]

The name "Bobbit worm" was coined in the 1996 book Coral Reef Animals of the Indo-Pacific, in reference to Lorena Bobbitt,[7] who was then very much in the public consciousness. The name is inspired only by the scissorlike jaws of the worm; the common supposition that female eunicids cut off the males' penises is false. In fact, the worms lack penises entirely as they are broadcast spawners.

References[edit]

  1. ^ Becky Crew (October 22, 2012). "Eunice aphroditois is rainbow, terrifying". Scientific American. Retrieved 2013-03-13. 
  2. ^ a b Simon, Matt (September 6, 2013). "Absurd Creature of the Week: 10-Foot Bobbit Worm Is the Ocean's Most Disturbing Predator - Wired Science". Wired.com. Retrieved 2013-09-09. 
  3. ^ SeaLifeBase (19 July 2012). Eunice aphroditois. Retrieved 3 June 2013.
  4. ^ Schulze, Anja (December 2011). "The Bobbit Worm Dilemma: A Case for DNA". Revista de Biología Tropical 59 (4): 1463–1474. Retrieved 7 September 2013. 
  5. ^ "Barry the giant sea worm discovered by aquarium staff after mysterious attacks on coral reef". Daily Mail (London). 2009-03-31. 
  6. ^ "Secret giant worm behind mystery of vanishing aquarium fish". The Telegraph. 18 October 2013. Retrieved 24 October 2013. 
  7. ^ "Who Named the Bobbit Worm (Eunice sp.)? And WHAT species is it.. truly??". 2014-08-13. 
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Notes

Possible hidden diversity encompassed in E. aphroditois

Early on in the taxonomic history of the eunicid worms, several specimens from around the world were synonymized into one species name (E. aphroditois).  This had the effect of assuming that certain characters had a large amount of variation in the species (e.g. antennal size, articulation of the antennae, type of pectinate chaetae type, maxillae teeth number (Salazar-Vallejo et al. 2011).  Thus even though, for example, specimens in Australia had very different branchial patterns and gut contents from those in the Phillipines, they were regarded as the same species. 

Salazar-Vallejo et al. 2011 believe that giant eunicid worms photographed from distinct geographies show morphological and behavioral differences that have not as yet been sufficiently analyzed, and historical lumping of these taxa may hide taxonomic diversity.  To fully resolve these taxonomic issues requires more understanding of variation (especially of diagnostic characters) in different populations.  Because type specimens have been lost over time, and because it is difficult to extract genetic information from embalmed organisms, Salazar-Vallejo et al. 2011) call for resampling at type localities, and using molecular and morphological methods in tandem to characterize possible hidden diversity.  These authors identify the following taxa as in particular need of attention: Eunice aphroditois (Sri Lanka), E. gigantea (La Reunion), E. kinbergi (Cape Town), E. longisetis (Bermuda), E. macrobranchia (Cape Town), E. maxima (Naples), E. nigricans (Jamaica), E. purpurea (Adriatic Sea), E. roussaei (Bay of Biscay), E. violacea (Pacific Costa Rica), and E. violaceomaculata (Florida), E. djiboutensis Gravier, 1900 and E. mutabilis Gravier, 1900 (Red Sea).

Some of the variation photographed includes:

Worms from the Phillipines and Indonesia: Dark bands on body; Median antenna same length as peristomal width; Banded anterior appendages; Fusiform peristomal cirri; Branchiae start by chaetiger 5; No white coloration on any anterior chaetigers

Worms from Australia: Body and appendages red in color; Median antennae 2-3 times the width of the peristome; Chaetiger 4 is white; Unknown as to which chaetiger is the start of branchiae.

A worm similar to E. torquata: Body solid red in color; Chaetiger 4 is pure white; Antennae are banded; median antennae 2-3 times the width of the peristome; Peristomal cirri are cirriform and whte; Branchiae start by chaetiger 3, pectinate by chaetiger 9.

Bengal eunicid (Indonesia): Gold and purple body coloring, with lines between segments and longitudinal along body; Chaetiger 4 is white; Solid gold-colored antennae, laterals just longer than the width of the peristome; Peristomial cirri are dark; Branchiae start by chaetiger 7.

Singapore eunicid: dark grey body, with spots mid-body; Chaetigers 4 and 5 have pale bands; Antennae, palps and cirri are pale, with dark tips; Branchiae start by chaetiger 7.

Caribbean eunicid (first form): Dark purple body with fine longitudinal lines; Banded appendages; Peristomal cirri are cirriform, banded; Pectinate branchiae, start at chaetiger 7.

Caribbean eunicid (2nd form): Body dark red with subtle banding on anterior appendages; peristomal cirri are cirriform; Pectinate branchiae, start at chaetiger 9; Younger individuals (and regenerated parts of older individuals) are purple.

Mediterranean Sea species (Eunice gigantea)
Pacific Coast of Central America (E. violacea)
Bay of Biscay/Mediterranean (E. roussaei)
Caribbean (E. violaceomaculata)

(Salazar-Vallejo et al. 2011)

  • Salazar-Vallejo, S.I., Carrera-Parra, L.F. and de León-González, A.J. 2011. Giant Eunicid Polychaetes (Annelida) in shallow tropical and temperate seas. Rev. Biol. Trop. 59-4: 1463-1474.
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