Phoronis hippocrepia Wright, 1856

Larva: Actinotrocha hippocrepia Silén, 1954


Phoronis (Crepina) gracilis van Beneden, 1858

Phoronis caespitosa Cori, 1889

Phoronis kowalevskii Benham, 1889

Phoronis capensis Gilchrist, 1907


About the species name hippocrepia:
    Wright (1856) wrote: "The tentacles were united at their base by a thick membrane, and were arranged in a crescent as in Polyzoan [former name of Bryozoa] of the Hippocrepian type."

    Hippocrepian: from Greek - hippos, a horse, and krépis, a shoe, a sole, means horse-shoe shaped.

° References of the most recent published diagnoses

Pictures of Phoronis hippocrepia


Last update: Septembre 7, 2006  

Extended specimens up to 100 mm long, diameter 0.3-1.5 mm.
Colour greenish-grey, yellowish or fleshy.
Lophophore horseshoe-shaped with the ends turned medially; the tentacles are up to 190 in number and 2-3 mm in length.
Nephridia with two funnels (the anal larger than the oral); a single ascending branch formed by two horizontal chambers, the upper one is the nephridial ridge opening by the nephridiopore above or at the level of the anus.
Two giant nerve fibre one on the left (diameter: 4-10 µm) and one on the right (diameter: 1-7 µm) occuring at the attachment of the lateral mesenteries to the body wall.
Longitudinal muscle bundles of bushy type; the mean formula and general formula are respectively:

11 | 11
 5  |  5
= 32  and  7-20 | 7-17
  3-9 | 3-10
[22-44]   (n= 409 individuals)

Sexual reproduction hermaphroditic; embryos brooded in two masses by the nidamental glands of A type (i.e. on the floor of the lophophoral concavity and on the inner surface of the internal tentacles); small lophophoral organs.
Asexual reproduction by transverse fission.

Phoronis hippocrepia is a burrowing and encrusting species inhabiting hard substrates i.e. rocks, empty mollusk shells, Caryophyllia (cup-corals), Lithothamnion (crustose coralline algae), wood.
Distribution ranges from the intertidal, near the low tide mark, to 55 m (generally 0-10 m); densities can reach more than 57 000 individuals/m2.

Phoronis hippocrepia: the distribution is represented below on the map.

Type-locality: Illfracombe (UK)

© Christian C. Emig

Last update: September 14, 2022

Distribution of P. hippocrepia

  •  Most recent published diagnoses

    Handbook of alien species in Europe (2009) : Comments on the so-called alien phoronid.

  •  Emig C. C., Roldán C. & J. M. Viéitez, 2005. Filo Phoronida. In: Fauna Ibérica, vol. 27. Museo de Ciencias Naturales, CSIC Madrid, p. 19-54 & 180-186 & 223-224.

  •  Zezina O. N. & S. N. Temereva, 2005. Brachiopoda and Phoronida. In: Biota of the Russian waters of the Sea of Japan, Ed. A. V. Adrianov, vol. 3, 138 p. Dalnauka, Vladivostock.

    Emig C. C., Çinar M. E. & Z. Ergen, 2003. Phoronida from the Eastern Mediterranean and Black Sea. Cahiers de Biologie Marine, 44 (2), 185-190.

    Breton G. & T. Vincent, 2002. La plongée subaquatique permet-elle d'évaluer de manière fiable la biodiversité de l'épibenthos dans un port ? Bull. Soc. zool. Fr. , 127 (2), 83-94.

    Emig C. C., Roldán & J. M. Viéitez, 2001. Phoronida. In: European Register of Marine Species, a check list of the marine species in Europe and a bibliography of guides to their identification, Costello M. J., Emblow C. & R. White (eds). Patrimoines Naturels, 50, 324-325.

    Breton G. & P. Breton, 2001. Flore et faune des ports de La Rochelle (Charente-Maritime). Bulletin de la Société géologique de Normandie et des Amis du Muséum du Havre , 87 (2-3), 87-91.

    Emig C. C., Roldán C. & J. M. Viéitez, 2000. Foronídeos del litoral luso-español. Phoronida from the Luso-Iberian zone. Boletín de la Real Sociedad Española de Historia Natural (Sec. Biol.), 96 (1-2), 77-83.

  •  Bailey-Brock J. H. & C. C. Emig, 2000. Hawaiian Phoronida (Lophophorata) and their distribution in the Pacific region. Pacific Science, 54 (2), 119-126.

    References on Phoronis hippocrepia

    Fig. 1 & 2 - Phoronis hippocrepia on open rock face, 20 m depth - Faial, Azores. Copyright Peter Wirtz.

    Dr. Peter Wirtz, PO Box 103, P - 9125 Canico, Madeira (Portugal)...
    see also his books and photos

    Fig. 3 & 4 - Phoronis hippocrepia, 11 m depth, at "Les Soldats", Pointe de Trévignon (29910, France).
    Copyright Mer et Littoral.

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