Bobbit worm
| Bobbit worm | ||||||||||||
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Bobbit worm ( Eunice aphroditois ) |
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| Eunice aphroditois | ||||||||||||
| ( Pallas , 1788) |
The Bobbitwurm ( Eunice Aphroditois ) belongs to the group of segmented worms from the class of polychaete and is mainly found in tropical waters . The nocturnal worm can reach a length of up to three meters, with only a small part sticking out of the sand on the ocean floor. The animal is usually found at a depth of ten to fifteen meters and lurks buried on the sea floor for prey.
features
It is an elongated, relatively slender polychaete (many bristles). The species usually reaches a body length of about one meter, but record specimens reach up to three meters and almost 700 segments. This makes the species one of the largest polychetes.
The body is dark purple in color in life, sometimes iridescent green, with a gray speckled pattern and a white-gray transverse band near the front end. The segments have short appendages ( parapodia ) on the sides , the shape of which changes gradually along the longitudinal axis of the body, without sharp transitions. The body is widest near the front end (about the level of the tenth segment) and narrows noticeably towards the rear. The front end is very muscular, it is used to move the large, protruding jaw apparatus. The body is almost round in the front section, sunk into a groove on the top, flat on the underside, and somewhat flattened in the less muscular middle section. The elongated rear section shows the simplified construction of the segments. The prostomium, which is quite short in the species, is bilobed and has five long tactile processes (antennae or palps) and around the mouth opening shorter cirrus, these are flattened basally in the species. On the side of the prostomium near the rear end there is a pair of round, dark-colored eyes. The peristomium is wider and covers the base of the prostomium on the top. The peristomium is divided into two parts, the posterior ring has two processes (cirrus). The jaw apparatus has a complex structure, consisting of a pair of mandibles with a sharp cutting edge and four pairs of coarsely toothed maxillae . The force of the jaws is enough to penetrate human skin. A muscular, extensible pharynx sits between the jaws . The body segments carry parapodia and on all segments up to near the rear end comb-shaped tube gills (Branchiae). The parapodia are two-branched, the branches of which carry thread-like cirrus, which are supported on the inside by skeletal needles (aciculae), in addition two-pointed subacicular hooks are present in the lower neuropodia . In this species, the aciculae are darkly colored towards the tip, the cirrus does not decrease in size towards the rear end. Since the body becomes narrower overall, they are therefore proportionally larger and more conspicuous. The second branch (neuropodium) is divided into several lobes.
Way of life
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The bobbit worm is predatory, other annelids, arrow worms , ostracods , copepods and mussels are given as prey , but also smaller fish; it may also be grazing the sediment surface. The bobbit worm also eats octopus, lionfish and even poisonous animals. Bobbit worms normally live within cavities of marine hard substrates, for example coral limestone, but occasionally occurrences of soft substrates such as sand are also reported.
In some places Eunice aphroditois is such an important predator for fish close to the ground that they have developed defensive strategies. The pseudo-snapper species Scolopsis affinis , native to the Indo-Pacific , is reported to have a social behavior known as "bullying" against carnivores , through which fish make their conspecifics aware of the danger posed by the bristle worm. If a fish has seen another one being eaten by the worm, it will stand at a safe distance vertically above the worm's head and spit a powerful gust of water against it. Several other fish come and jointly give violent rushes of water against the predator, so that the predator has to retreat deep into his tube, but at the same time all fish that are present become aware of the danger spot and now avoid it.
The species is occasionally introduced with live rock into seawater aquariums, where it can cause serious damage due to its predatory diet.
distribution
The species is distributed worldwide in warm marine areas. It is given north to Japan ( Hokkaidō ), to the Caribbean and to the Mediterranean (Northern Adriatic).
Taxonomy
The genus Eunice comprises about 220 mostly difficult to distinguish species and is distributed worldwide. The species was first described by Peter Simon Pallas in 1788 as Nereis aphroditois , the type locality is a coral reef near Sri Lanka . The species is a type of the genus Eunice (sensu stricto). A common synonym is Leodice gigantea . The species name used so far may actually include several species that have not yet been distinguished.
Naming
The first description of the species was published by Peter Simon Pallas in 1788 , as a species of the genus Nereis and named as Nereis aphroditois . Later it was placed in the genus Eunice named by Georges Cuvier in 1817 .
The name of the genus Eunice alludes to the animals' acquisition of food and refers to Euneike , a nymph who, according to Greek mythology , drew the young Hylas down into the depths of their source when they drew water. The epithet aphroditois refers to Aphrodite , the Greek goddess of love , beauty and sensual desire , which , according to Hesiod , arose in the sea from the blood and sperm of Uranos , whose son Kronos - on the advice of his mother Gaia - the genitals with one Cut sickle and thrown into the sea.
The name Bobbit (t) or Bobbit (t) worm took up these myths and was developed by the zoologist and marine biologist Terrence M. Gosliner ( California Academy of Sciences ) in the course of work on his textbook Coral Reef Animals of the Indo-Pacific , published in 1996 embossed. The name refers to a worldwide sensational criminal case in the USA in 1993 when Lorena Bobbitt cut off the penis of her husband John Wayne Bobbitt.
See also
swell
- Kristian Fauchald (1992): A Review of the Genus Eunice (Polychaeta: Eunicidae) Based upon Type Material . Smithsonian Contributions to Zoology Number 523.
Web links
- Eunice aphroditois at WoRMS World Register of Marine Species (English)
- Keith Davey: Life on Australian Seashores: Eunice aphroditois. Accessed March 7, 2018
- Fish defend themselves against monster worms. On: unibas.ch September 20, 2016
Individual evidence
- ↑ Hiroomi Uchida, Hidetomo Tanase, Shin Kubota (2009): An extraordinarily large specimen of the polychaete worm Eunice aphroditois (Pallas) (Order Eunicea) from Shirahama, Wakayama, central Japan . Kuroshio Biosphere 5: 9-15.
- ↑ Kristian Fauchald & Peter A. Jumars (1979): The diet of worms: a study of polychaete feeding guilds . Oceanography and marine biology: an annual review 17: 193-284.
- ↑ a b Jose Lachat, Daniel Haag-Wackernagel (2016): Novel mobbing strategies of a fish population against a sessile annelid predator. Scientific Reports 6, Article number: 33187 doi: 10.1038 / srep33187 (open access)
- ↑ a b Daniela Zeibig: Fish bully monster worms. The bobbit worm hunts in the sea and attacks fish from ambush. But its prey knows how to defend itself. Spektrum.de, September 21, 2016.
- ^ Sandra Casellato & Antonio Stefanon (2008): Coralligenous habitat in the northern Adriatic Sea: an overview . Marine Ecology 29: 321-341.
- ↑ Joana Zanol, Kristian Fauchald, Paulo C. Paiva (2007): A phylogenetic analysis of the genus Eunice (Eunicidae, polychaete, Annelida) . Zoological Journal of the Linnean Society 150: 413-434.
- ^ Sergio I. Salazar-Vallejo, Luis F. Carrera-Parra, J. Angel de León-González (2011): Giant Eunicid Polychaetes (Annelida) in shallow tropical and temperate seas . Revista de Biología Tropical vol. 59, n.4: 1463-1474.
- ↑ Terrence M. Gosliner, David W. Behrens and Gary C. Williams: Coral Reef Animals of the Indo-Pacific: Animal Life from Africa to Hawai'i Exclusive of the Vertebrates. Sea Challengers Inc., Monterey (California) 1996, ISBN 978-0930118211
- ↑ Bobbit: The sinister sea creature that left Blue Planet 2 viewers terrified. On: independent.co.uk on November 13, 2017
- ↑ Between the legs. The severed penis trial confronts America's men with their deepest fears. On: spiegel.de from January 17, 1994