Myzostomatida

Myzostoma cirriferum, from Christoph Bleidorn.

Belongs within: Aciculata.

The Myzostomatida are a group of small marine worms that live in close association with echinoderms, either as commensals or parasites (Lanterbecq et al. 2006).

Characters (from Lanterbecq et al. 2006): Anterior introvert present. Trunk with five pairs of conical locomotory organs (parapodia) with distal hook-shaped chaeta and basal parapodial fold, alternating with four pairs of lateral sense organs; parapodia and lateral organs may be reduced or lost in parasitic forms.

<==Myzostomatida [Endomyzostomatidae, Myzostomida]
    |  i. s.: Stelechopus [Stelechopidae] LR06
    |           `--S. hyocrini LR06
    |         Mycomyzostoma calcidicola LR06
    |--Pharyngidea LR06
    |    |--Pulvinomyzostomum [Pulvinomyzostomatidae] LR06
    |    |    `--P. pulvinar (Graff 1884) LR06 [=Myzostoma pulvinar BK77]
    |    `--Endomyzostoma LR06
    |         |--E. cysticolum (Graff 1883) LR06
    |         `--+--E. deformator (Graff 1884) LR06
    |            `--+--E. clarki (McClendon 1906) LR06
    |               `--E. tenuispinum (Graff 1884) LR06
    `--Myzostoma LR06 [=Myzostomum Leuckart 1827 BK77, H62; Myzostomatidae]
         |  i. s.: ‘*Myzostomum’ costatum Leuckart 1827 H62
         |         M. agassizii von Graff 1883 C50
         |         ‘Myzostomum’ brevipes C50
         |         M. carpenteri [=Myzostomum carpenteri] BK77
         |         M. fimbriatum [=Myzostomum fimbriatum] BK77
         |         M. giganteum [=Myzostomum giganteum] BK77
         |         M. gigas [=Myzostomum gigas] BK77
         |         M. graffi [=Myzostomum graffi] BK77
         |         ‘Myzostomum’ parasiticum [incl. Myzostoma tuberculosum Semper 1858] BK77
         |         ‘Myzostomum’ pictum von Graff 1884 C50
         |         M. seymourcollegiorum DH08
         |--+--M. cirriferum (Leuckart 1827) LR06 (see below for synonymy)
         |  `--+--M. alatum (Graff 1884) LR06 [=Myzostomum alatum BK77]
         |     `--M. glabrum (Leuckart 1842) LR06
         `--+--+--+--Notopharyngoides aruensis (Remscheid 1918) LR06
            |  |  `--+--M. cuniculus (Eeckhaut, Grygier & Deheyn 1998) LR06
            |  |     `--M. pseudocuniculus (Lanterbecq & Eeckhaut 2003) LR06
            |  `--+--Contramyzostoma sphaera (Eeckhaut, Grygier & Deheyn 1998) LR06
            |     `--+--M. capitocutis (Eeckhaut, VandenSpiegel & Grygier 1994) LR06
            |        `--+--M. coriaceum (Graff 1884) LR06
            |           `--M. nigromaculatum (Eeckhaut, Grygier & Deheyn 1998) LR06
            `--+--+--+--M. polycyclus (Atkins 1927) LR06
               |  |  `--M. toliarense (Lanterbecq & Eeckhaut 2003) LR06
               |  `--+--M. ambiguum (Graff 1887) LR06
               |     `--+--M. mortenseni (Jägersten 1842) LR06
               |        `--+--Asteriomyzostomum [Asteriomyzostomatidae] LR06
               |           `--Asteromyzostomum [Asteromyzostomatidae] LR06
               `--+--+--+--M. fissum (Graff 1884) LR06
                  |  |  `--M. furcatum (Graff 1887) LR06
                  |  `--Hypomyzostoma LR06
                  |       |--H. crosslandi (Boulenger 1913) LR06
                  |       |--H. dodecephalcis (Grygier 1992) LR06
                  |       `--H. fasciatum (Remscheid 1918) LR06
                  `--+--M. laingense (Eeckhaut, Grygier & Deheyn 1998) LR06
                     `--Mesomyzostoma [incl. Protomyzostomum; Mesomyzostomatidae, Protomyzostomatidae] LR06
                          |  i. s.: ‘Protomyzostomum’ sagamiense BK77
                          |--‘Protomyzostomum’ polynephris (Fedotov 1912) LR06 [=Protomyzostoma polynephris BK77]
                          `--+--M. reichenspergi (Remscheid 1918) LR06
                             `--+--‘Protomyzostomum’ glanduliferum (Bartsch 1995) LR06
                                `--M. katoi (Okada 1933) LR06

Myzostoma cirriferum (Leuckart 1827) LR06 [=Myxostoma (l. c.) cirriferum BK77, Myzostomum cirriferum BK77; incl. Myzostomum schultzeanum Diesing 1858 BK77, Cyclocirra thompsonii Müller 1841 BK77, Myzostomum thompsoni BK77]

*Type species of generic name indicated

REFERENCES

[BK77] Barel, C. D. N., & P. G. N. Kramers. 1977. A survey of the echinoderm associates of the north-east Atlantic area. Zoologische Verhandelingen 156: 1–159.

[C50] Clark, A. H. 1950. A monograph of the existing crinoids. Vol. 1. The comatulids. Part 4c. Superfamily Tropiometrida (the families Thalassometridae and Charitometridae). Bulletin of the United States National Museum 82 vol. 1 (4c): 1–383.

[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.

[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.

[LR06] Lanterbecq, D., G. W. Rouse, M. C. Milinkovitch & I. Eeckhaut. 2006. Molecular phylogenetic analyses indicate multiple independent emergences of parasitism in Myzostomida (Protostomia). Systematic Biology 55 (2): 208–227.