''Aspidosiphon elegans'' is a species of unsegmented benthic marine worm in the phylum

Sipuncula The Sipuncula or Sipunculida (common names sipunculid worms or peanut worms) is a class containing about 162 species of unsegmented marine annelid worms. The name ''Sipuncula'' is from the genus name '' Sipunculus'', and comes from the Latin ...

, the peanut worms. It is a bioeroding species and burrows into limestone rocks, stones and corals. It occurs in the western Indo-Pacific region, the Red Sea, and the tropical western Atlantic Ocean, and is invasive in the eastern Mediterranean Sea.

Description

''Aspidosiphon elegans'' can grow up to in length, but is a more usual size. The introvert is at least as long as the trunk and both are smooth and white. The tip of the introvert bears the oral disc with the mouth and six to twelve short

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s. The

distal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

part of the introvert bears rings of two-pronged hooks while the

proximal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position ...

part bears scattered, dark-coloured conical hooks. The anal shield is ungrooved while the caudal shield is poorly developed and paler in colour than the anal shield. There are a pair of light-sensitive eye spots and a pair of

nephridia The nephridium (plural ''nephridia'') is an invertebrate organ, found in pairs and performing a function similar to the vertebrate kidneys (which originated from the chordate nephridia). Nephridia remove metabolic wastes from an animal's body. Neph ...

Distribution and habitat

This peanut worm is found in shallow waters in the northwestern Indian Ocean and the Red Sea, and the

Levantine Sea The Levantine Sea (Arabic: بحر الشام, tr, Levanten Denizi, el, Θάλασσα του Λεβάντε) is the easternmost part of the Mediterranean Sea. Geography The Levantine Sea is bordered by Turkey in the north and north-east co ...

, having arrived there at the latest by 1957 after the opening of the Suez Canal. It also occurs on the Atlantic coast of Central America, but not on the Pacific coast. It is a bioeroding organism and burrows into limestone rocks and stones, as well as coral heads, coralline algae and the shells of

bivalve molluscs Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biva ...

Ecology

In the Mediterranean Sea, this species was found burrowing in calcareous rocks, in coralline algae (''

Corallina mediterranea ''Corallina'' is a genus of red seaweeds with hard, abrasive calcareous skeletons in the family Corallinaceae. They are stiff, branched plants with articulations. Species # ''Corallina aberrans'' (Yendo) K.R.Hind & G.W.Saunders # ''Coralli ...

'') and in the mussel (''

Brachidontes pharaonis ''Brachidontes pharaonis'' is a species of mussel from the family Mytilidae. It is native to the Indian Ocean and the Red Sea, and has colonised the Mediterranean Sea where it is regarded as an invasive species. Description ''Brachidontes pharao ...

''), another organism that has invaded the Mediterranean via the Suez Canal. In this locality, there were said to be 25 individuals per square metre. Reproduction in this species is by transverse

fission Fission, a splitting of something into two or more parts, may refer to: * Fission (biology), the division of a single entity into two or more parts and the regeneration of those parts into separate entities resembling the original * Nuclear fissio ...

; a constriction appears at the posterior end of the trunk, gradually deepening until the part becomes detached, with

regeneration Regeneration may refer to: Science and technology * Regeneration (biology), the ability to recreate lost or damaged cells, tissues, organs and limbs * Regeneration (ecology), the ability of ecosystems to regenerate biomass, using photosynthesis ...

of the main body components then following.

References

{{Taxonbar, from=Q1810419 Sipunculans Fauna of the Atlantic Ocean Fauna of the Indian Ocean Fauna of the Red Sea Animals described in 1821 Taxa named by Adelbert von Chamisso