Sipuncula

Aspidosiphon sp., copyright Moorea Biocode.

Belongs within: Annelida.

The Sipuncula, peanut worms, are a group of marine worms with a retractile proboscis (Howell 1962). Though often treated as a distinct 'phylum' within the animals, recent analyses have suggested that they may be derived annelids that have secondarily lost segmentation.

Characters (from Howell 1962): Body unsegmented or poorly segmented, cylindrical or subcylindrical; retractile introvert present at anterior end, may be armed with chitinous hooks.

<==Sipuncula [Sipunculoidea]
    |  i. s.: Epitrachys Ehlers 1869 H62
    |           `--*E. rugosus Ehlers 1869 H62
    |         Lecathylus Weller 1925 H62
    |           `--*L. gregarius Weller 1925 H62
    |         Schizoproboscina Yakovlev 1939 H62
    |           `--*S. ivanovi Yakovlev 1939 H62
    |         Stoma Hadding 1913 H62
    |           `--*S. hians Hadding 1913 H62
    |         ‘Protholothuria’ annulata FE66
    |--Archaeogolfingia EL11
    `--+--Sipunculida GD00
       |    |--Sipunculidae [Sipunculiformes] CG85
       |    |    |--Phascolopsis gouldi (Pourtalès 1851) CG85, SS07
       |    |    `--+--+--Siphonomecus CG85
       |    |       |  `--Siphonosoma CG85
       |    |       `--+--Sipunculus CG85
       |    |          |    |--S. maoricus HS01
       |    |          |    `--S. nudus KC11
       |    |          `--Xenosiphon CG85
       |    `--Golfingiaformes CG85
       |         |--Themiste [Themistidae] CG85
       |         |    |--T. alutacea GD00
       |         |    |--T. lageniformis DH08
       |         |    `--T. minor HS01
       |         |         |--T. m. minor HS01
       |         |         `--T. m. huttoni HS01
       |         `--+--Phascolionidae CG85
       |            |    |--Phascolion PH06
       |            |    |    |--P. convestitus H15
       |            |    |    |--P. spitzbergense H15
       |            |    |    `--P. strombi PH06
       |            |    `--Onchnesoma CG85
       |            `--Golfingiidae CG85
       |                 |--Golfingia CG85
       |                 |    |--G. elongata (Keferstein 1862) RP07
       |                 |    |--G. gouldii GR98
       |                 |    |--G. margaritacea CG85
       |                 |    `--G. vulgaris CG85
       |                 `--+--Thysanocardia nigra CG85
       |                    `--Nephasoma CG85
       |                         |--N. minuta CG85
       |                         `--N. rimicola CG85
       `--Phascolosomida GD00
            |--Phascolosomatidae [Phascolosomaformes] CG85
            |    |--Apionsoma misakianum CG85, PH06
            |    `--+--Antillesoma antillarum (Grube & Öersted 1858) CG85, RP07
            |       `--Phascolosoma CG85
            |            |--P. antillarum CH97
            |            |--P. australe H15
            |            |--P. eremita H15
            |            |--P. granulatum ZHT01
            |            |--P. japonica KBC03
            |            `--P. pellucidum H15
            `--Aspidosiphonidae [Aspidosiphoniformes] CG85
                 |--Cloeosiphon aspergillus (Quatrefages 1865) CG85, RP07
                 `--+--Lithacrosiphon CG85
                    `--Aspidosiphon CG85
                         |--A. albus Murina 1967 E86
                         |--A. clavatus M62
                         |--A. exiguus Edmonds 1974 E86
                         |--A. misakiensis GD00
                         |--A. spinalis E86
                         `--A. zinni E86

*Type species of generic name indicated

REFERENCES

[CH97] Castro, P., & M. E. Huber. 1997. Marine Biology 2^nd ed. WCB McGraw-Hill: Boston.

[CG85] Cutler, E. B., & P. E. Gibbs. 1985. A phylogenetic analysis of higher taxa in the phylum Sipuncula. Systematic Zoology 34 (2): 162–173.

[DH08] Dunn, C. W., A. Hejnol, D. Q. Matus, K. Pang, W. E. Browne, S. A. Smith, E. Seaver, G. W. Rouse, M. Obst, G. D. Edgecombe, M. V. Sørensen, S. H. D. Haddock, A. Schmidt-Rhaesa, A. Okusu, R. M. Kristensen, W. C. Wheeler, M. Q. Martindale & G. Giribet. 2008. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature 452: 745–749.

[E86] Edmonds, S. J. 1986. Sipuncula. In: Botosaneanu, L. (ed.) Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) p. 209. E. J. Brill/Dr W. Backhuys: Leiden.

[EL11] Erwin, D. H., M. Laflamme, S. M. Tweedt, E. A. Sperling, D. Pisani & K. J. Peterson. 2011. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science 334: 1091–1097.

[FE66] Frizzell, D. L., & H. Exline. 1966. Holothuroidea—fossil record. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U646–U672. The Geological Society of America, Inc., and The University of Kansas Press.

[GD00] Giribet, G., D. L. Distel, M. Polz, W. Sterrer & W. C. Wheeler. 2000. Triploblastic relationships with emphasis on the acoelomates and the position of Gnathostomulida, Cycliophora, Plathelminthes, and Chaetognatha: a combined approach of 18S rDNA sequences and morphology. Systematic Biology 49: 539–562.

[GR98] Giribet, G., & C. Ribera. 1998. The position of arthropods in the animal kingdom: a search for a reliable outgroup for internal arthropod phylogeny. Molecular Phylogenetics and Evolution 9: 481–488.

[H15] Harmer, S. F. 1915. The Polyzoa of the Siboga Expedition—Part I. Entoprocta, Ctenostomata and Cyclostomata. E. J. Brill: Leyden.

[HS01] Hayward, B. W., A. B. Stephenson, M. S. Morley, W. M. Blom, H. R. Grenfell, F. J. Brook, J. L. Riley, F. Thompson & J. J. Hayward. 2001. Marine biota of Parengarenga Harbour, Northland, New Zealand. Records of the Auckland Museum 37: 45–80.

[H62] Howell, B. F. 1962. Worms. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt W. Miscellanea: Conodonts, Conoidal Shells of Uncertain Affinities, Worms, Trace Fossils and Problematica pp. W144–W177. Geological Society of America, and University of Kansas Press.

[KBC03] Kashin, I. A., E. V. Bagaveeva & S. F. Chaplygina. 2003. Fouling communities of hydrotechnical constructions in Nakhodka Bay (Sea of Japan). Russian Journal of Marine Biology 29: 267–283.

[KC11] Kocot, K. M., J. T. Cannon, C. Todt, M. R. Citarella, A. B. Kohn, A. Meyer, S. R. Santos, C. Schander, L. L. Moroz, B. Lieb & K. M. Halanych. 2011. Phylogenomics reveals deep molluscan relationships. Nature 477: 452–456.

[M62] Monniot, F. 1962. Recherches sur les graviers a Amphioxus de la région de Banyuls-sur-Mer. Vie et Milieu 13: 231–322.

[PH06] Passamaneck, Y., & K. M. Halanych. 2006. Lophotrochozoan phylogeny assessed with LSU and SSU data: evidence of lophophorate polyphyly. Molecular Phylogenetics and Evolution 40 (1): 20–28.

[RP07] Rousset, V., F. Pleijel, G. W. Rouse, C. Erséus & M. E. Siddall. 2007. A molecular phylogeny of annelids. Cladistics 23: 41–63.

[ZHT01] Zrzavý, J., V. Hypša & D. F. Tietz. 2001. Myzostomida are not annelids: molecular and morphological support for a clade of animals with anterior sperm flagella. Cladistics 17: 170–198.