Phylum Sipuncula In: Atkinson LJ and Sink KJ (eds). Field Guide to the Ofshore Marine Invertebrates of South Africa,. Malachite Marketing and Media, Pretoria. Sipuncula is a clade of unsegmented, coelomate marine worms. . Sipuncula, however, with sipunculans as an annelid ingroup, other. Phylum Sipuncula. Class Phascolosomatidea. Order Aspidosiphoniformes. Family Aspidosiphonidae. Aspidosiphon Diesing, Aspidosiphon elegans.

Author: Nejar Nejin
Country: Egypt
Language: English (Spanish)
Genre: Music
Published (Last): 13 March 2014
Pages: 85
PDF File Size: 11.20 Mb
ePub File Size: 5.15 Mb
ISBN: 472-5-78847-855-4
Downloads: 33782
Price: Free* [*Free Regsitration Required]
Uploader: Vishura

Three genera AspidosiphonLithacrosiphon and Cloeosiphon in the Aspidosiphonidae family, possess epidermal structures modified for boring into rock; the sipunculq shield is near the anteriorly located anus on the trunk just below the introvert of the animal. From Wikipedia, the free encyclopedia. Xenacoelomorpha Xenoturbellida Xenoturbella Acoelomorpha acoels zipuncula.

Molecular Biology and Evolution. The specimen was dissected by Lankester between rounds of golf at Saint Andrews golf club in Scotland from which the species derives its name. Some scientists once hypothesized a close relationship between sipunculans and the extinct hyolithsoperculate shells from the Palaeozoic with which they share a helical gut; but this hypothesis has since been discounted.

Phylum Sipuncula

sipncula Sipuncula signifies “little tube or siphon”. Sipunculans occur in cold, temperate and tropical marine benthic habitats. The Sipuncula or Sipunculida common names sipunculid worms or peanut worms is a group containing — species estimates vary of bilaterally symmetricalunsegmented marine worms.

The sipunculan nervous system consists of a cerebral ganglion and a ventral nerve cord. Kinorhyncha mud dragons Priapulida penis worms.

Fioum Dicyemida or Rhombozoa Monoblastozoa Salinella. Proceedings of the Royal Society B: At the posterior end of the trunk, a hardened caudal shield is sometimes present in Aspidosiphon ; [6] this may help with anchoring the animal in its burrow or may be used in the boring process.


Relatively little is known about the behavior of sipunculans.

Siphncula from ” https: Phylogenetic analyses based on 79 ribosomal proteins indicated a position of Sipuncula within Annelida. Originally classified as annelidsdespite the complete lack of segmentation, bristles and other annelid characters, the phylum Sipuncula was later allied with the Molluscamostly on the basis of developmental and larval characters.

Number of families 6 Thumbnail description Unsegmented marine worm-like animals with a body divided into a trunk and retractable introvert Photo: It filym be protruded from the trunk by contracting the muscles of the trunk wall, thus forcing the fluid in the body cavity forwards. The worms stay submerged in the sea bed between 10 and 18 hours a day and are sensitive to salinity, and thus not commonly found near estuaries.

In some species, there are simple light-sensitive ocelli associated with the brain. When the introvert is retracted in these animals, the anal shield blocks the entrance to its burrow. Dioecious; indirect developer with lecithotrophic trochophore and long-lived fium pelagosphera. Ecdysozoa Scalidophora Kinorhyncha mud dragons Priapulida penis worms.

The sipunculan body is divided into trunk and retractable introvert. The specimen was provided by a friend of his, Professor Mackintosh. Skpuncula threatened, Sipunculids can contract their body into a shape resembling a peanut kernel —a practice that has given rise to the name “peanut worm”. Wikimedia Sjpuncula has media related to Sipuncula. In the early seventeenth century, Sipuncula were considered close relatives of holothurians.

List of bilaterial animal orders.


Others inhabit empty mollusk shells, polychaete tubes, foraminiferan tests, or barnacles. Rock-dwelling species use their introvert hooks, mostly at nighttime, to scrape sediment and epifaunal organisms from the surrounding rock surface.

Golfingia is now the genus name and Sipuncula the name of the phylum to which these worms belong. In Java, in the western Carolines, and in some parts of China, sipunculans are eaten by the locals. Sipunculla rectal caecum, present in most species, is a blind ending sac at the transition between intestine and rectum with unknown function.

Phylum Sipuncula

The planktotrophic pelagosphera lasts up to six months in the water column before settling. Burrowing and crawling are accomplished flium utilizing the introvert hooks as anchors and the introvert musculature to pull the body forward. This style of food preparation is locally called kilawin or kinilawand is also done for fish, conch, and vegetables. It is attached anteriorly to the body wall near the anus and posteriorly to either the body wall or inside the gut coil.

Fishermen in various parts of the world use sipunculan worms, mostly the larger sand-dwelling species, as bait. Algal mats, large sponges, root mats of mangroves or sea grass, and byssal threads of bivalves also serve as habitats for some species. Most sipunculan species are dioecious. Fikum considered wipuncula phylumthey might be a subgroup of phylum Annelida based on recent molecular work.