Holothuroidea

Specimen of Molpadia musculus, photographed by Carlo Fiori.

Belongs within: Eleutherozoa.
Contains: Priscopedatidae, Elasipodida, Aspidochirotida, Dendrochirotacea, Apodida.

The Holothuroidea include the sea cucumbers, echinoderms in which the characteristic pentaradial symmetry of the phylum has been superimposed by a secondary bilaterality. Holothuroids have also reduced the skeletal plates to become much more flexible than other echinoderms. In members of the Apodacea, the tube feet have also been reduced or lost; mobility is by means of projecting anchor sclerites (Pawson 1966). The tentacles surrounding the mouth are modified in many holothuroid lineages; Apodacea retain simple digitate or pinnate tentacles but in Aspidochirotacea (Aspidochirotida and Elasipodida) they terminate in an approximately circular disc (Pawson 1966).

Characters (from Ubaghs 1978): Mostly free-living, usually with body elongated in oral-aboral axis and secondary bilateral symmerry; mouth encircled by tentacles; pharynx surrounded· by calcareous ring; ambulacral grooves lacking; skeleton ordinarily consisting of microscopic sclerites embedded in body wall; gonad single.

<==Holothuroidea (see below for synonymy)
    |--Aspidochirotacea U78
    |    |  i. s.: Priscopedatidae P66
    |    |--Elasipodida S97
    |    `--+--Aspidochirotida S97
    |       `--Dendrochirotacea S97
    `--Apodacea U78
         |--Apodida S97
         `--Molpadida U78
              |  i. s.: Cherbonniera utriculus Sibuet 1974 B01
              |         Paracaudina F67
              |         Calcligula Frizzell & Exline 1956 P66, FE66 [incl. Molpadioites Deflandre-Rigaud 1961 FE66]
              |           |--*C. perforata Frizzell & Exline 1956 FE66
              |           |--C. elgeri FE66
              |           |--C. ficta FE66
              |           `--C. jurassica FE66
              |--Gephyrothuriidae P66
              |--Exlinellidae P66
              |    |--Exlinella Deflandre-Rigaud 1961 FE66
              |    |    `--*E. frizzelli Deflandre-Rigaud 1961 FE66
              |    `--Pedatopriscus Deflandre-Rigaud 1961 FE66
              |         `--*P. pinguis (Deflandre-Rigaud 1946) [=Priscopedatus pinguis] FE66
              |--Caudinidae MG-H11
              |    |--Acaudina leucoprocta (Clark 1938) MG-H11
              |    |--Caudina coriacea H04
              |    `--Aphelodactyla MG-H11
              |         |--A. bacilla (Cherbonnier & Féral 1981) MG-H11
              |         |--A. molpadioides (Semper 1868) MG-H11
              |         `--A. suspecta (Cherbonnier & Féral 1981) MG-H11
              `--Molpadiidae MG-H11
                   |--Heteromolpadia tridens (Sluiter 1901) MG-H11
                   |--Trochostoma Danielsen & Koren 1878 MG-H11, B01
                   |    `--T. parvulum Cherbonnier & Féral 1981 MG-H11
                   `--Molpadia MG-H11
                        |--M. andamanensis (Walsh 1981) MG-H11
                        |--M. musculus Risso 1826 MG-H11
                        `--M. oolitica BK77

Holothuroidea incertae sedis:
  Stereoderma unisemita K-M02
  Pseudocucumis mixta W79
  Protancyra challengeri J18
  Patinapta ooplax (Marenzeller 1881) S-PR86
  Ocellothuria Boczarowski 2001 B01
    `--*O. binoculata Boczarowski 2001 B01
  Canisia Mostler 1972 B01
  Triradites Mostler 1969 B01
  Pseudothyone sculponea Cherbonnier 1958 B01
  Andenothyone gondwanensis Haude 1995 B01
  Nudicorona seilacheri Haude 1995 B01
  Bathyplotes natans BK77
  Palaeocucumariidae [Arthrochirotida, Etheridgellidae] B01
    |--Frizzellus Hampton 1958 FE66
    |    `--*F. irregularis Hampton 1958 FE66
    |--Etheridgella Croneis 1932 B01, FE66
    |    |--*E. porosa Croneis 1932 FE66
    |    `--E. biconvexa FE66
    `--Palaeocucumaria Lehmann 1958 B01
         |--*P. hunsrueckiana Lehmann 1958 B01
         |--P. ancile Boczarowski 2001 B01
         `--P. delicata Boczarowski 2001 B01
  Cucumeria MW07
    |--C. salva MW07
    `--C. sykion MW07
  Kaliobullites Kristan-Tollmann 1963 [Kaliobullitidae] FE66
    `--*K. umbo Kristan-Tollmann 1963 FE66
  Calcancorella Deflandre-Rigaud 1961 [Calcancorellidae] FE66
    `--*C. spectabilis (Deflandre-Rigaud 1959) [=Synaptites (Calcancora) spectabilis] FE66
  Alexandrites Kristan-Tollmann 1964 [Alexandritidae] FE66
    `--*A. alexandri Kristan-Tollmann 1964 FE66

Holothuroidea [Ascidiastella, Cylindroides, Fistulidae, Fistulides, Holothuriacea, Holothuriadae, Holothuriae, Holothurida, Holothuridae, Holothuridea, Holothurina, Holothurioidea, Holothuromorpha, Scytactinata, Scytodermata]

*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.

[B01] Boczarowski, A. 2001. Isolated sclerites of Devonian non-pelmatozoan echinoderms. Palaeontologia Polonica 59: 1–219.

[F67] Fell, H. B. 1967. Echinoderm ontogeny. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt S. Echinodermata 1. General characters. Homalozoa—Crinozoa (except Crinoidea) vol. 1 pp. S60–S85. The Geological Society of America, Inc., and The University of Kansas: Lawrence (Kansas).

[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.

[H04] Haeckel, E. 1899–1904. Kunstformen der Natur. Bibliographisches Institut: Leipzig und Wien.

[J18] Jaekel, O. 1918. Phylogenie und System der Pelmatozoen. Paläontologische Zeitschrift 3: 1–128.

[K-M02] Klein-MacPhee, G. 2002. Righteye flounders. Family Pleuronectidae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3^rd ed. pp. 560–587. Smithsonian Institute Press: Washington.

[MW07] Mallatt, J., & C. J. Winchell. 2007. Ribosomal RNA genes and deuterostome phylogeny revisited: more cyclostomes, elasmobranchs, reptiles, and a brittle star. Molecular Phylogenetics and Evolution 43: 1005–1022.

[MG-H11] McEnnulty, F. R., K. L. Gowlett-Holmes, A. Williams, F. Althaus, J. Fromont, G. C. B. Poore, T. D. O’Hara, L. Marsh, P. Kott, S. Slack-Smith, P. Alderslade & M. V. Kitahara. 2011. The deepwater megabenthic invertebrates on the western continental margin of Australia (100–1100 m depths): composition, distribution and novelty. Records of the Western Australian Museum Supplement 80: 1–191.

[P66] Pawson, D. L. 1966. Phylogeny and evolution of holothuroids. In: Moore, R. C. (ed.) Treatise on invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U641–U646. The Geological Society of America, Inc., and The University of Kansas Press.

[S-PR86] Salvini-Plawen, L. v., & G. C. Rao. 1986. Echinoderma. In: Botosaneanu, L. (ed.) Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) pp. 701–704. E. J. Brill/Dr W. Backhuys: Leiden.

[S97] Smith, A. B. 1997. Echinoderm larvae and phylogeny. Annual Review of Ecology and Systematics 28: 219–241.

[U78] Ubaghs, G. 1978. Classification of the echinoderms. In: Moore, R. C., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt T. Echinodermata 2. Crinoidea vol. 1 pp. T359–T367. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[W79] Warner, G. F. 1979. Aggregation in echinoderms. In: Larwood, G., & B. R. Rosen (eds) Biology and Systematics of Colonial Organisms pp. 375–396. Academic Press: London.