Schulze, 1880

Species Overview

Plakortis simplex Schulze (1880) is a thinly encrusting, smooth, brownish crust with regularly distributed tiny holes on the surface. Its spiculation is unique. It is a Mediterranean species with several records from Western Europe (Roscoff and SW Ireland).

Taxonomic Description

Colour: Tan outside, whitish inside.
Shape, size, surface and consistency: Thinly encrusting, generally 2-5 mm in thickness. Surface smooth and regularly pierced by small punctiform inhalant openings. Oscules about 1 mm in diameter and low in frequency. Consistency compressible.
Spicules: (Plakortis simplex spics) Centrotylote diods, somewhat sinuous: 60-150 x 3-6 µm; rare triods with rays 25-50 x 3-6 µm.
Skeleton: Spicules are packed throughout the sponge, around small choanocyte chambers.
Ecology: On and under rocks and boulders from the littoral to at least 15 m.
Distribution: Mediterranean, West Africa, Roscoff, SW Ireland, Norway; reported from all over the world, but these are probably closely related species.
Etymology: The name refers to the simple shape of the spicules as compared to those of Plakina and Plakinastrella species, which were described in the same publication.
Type specimen information: No type material in BMNH.

Remarks

The thin smooth crusts with regularly distributed holes is fairly distinctive, but microscopic examination is necessary. The spicules are unique, although Plakina monolopha is close; however that species has lophotriaenes.
Sources: Topsent, 1895; Díaz and Van Soest, 1994.

Kingdom Animalia
Phylum Porifera
Class Demospongiae
Order Homosclerophorida
Family Plakinidae
Genus Plakortis
Species Plakortis simplex

Status in World Register of Marine Species

Accepted name: Plakortis simplex Schulze, 1880

Scientific synonyms and common names

Plakortis simplex n.sp. Schulze, 1880: 430; Topsent, 1895: 557, fig. 7; Stephens, 1914: 10; Burton, 1930a: 488; Borojevic et al., 1968: 5; Díaz and Van Soest, 1994: 104.

Borojevic, R., L. Cabioch and C. Lévi, 1968. Spongiaires. Inventaire Faune Marine de Roscoff. 44 pp.

Burton, M., 1930a. Norwegian sponges from the Norman collection. Proc. zool. Soc. London, 2: 487-546.

Cruz, T. and J.J. Bacallado, 1981. Contribucion al conocimiento de los espongiarios de las Islas Canarias. I. Demosponjas Homosclerophorida y Astrophorida del litoral de Tenerife. Bol. Inst. Esp. Oceano. 6: 76-87.

Díaz, M.C. and R.W.M. van Soest, 1994. The Plakinidae: A systematic review: 93-109. In: R.W.M. van Soest, Th. M.G. van Kempen and J.C. Braekman, eds. Sponges in time and space. Balkema, Rotterdam: i-xviii,1-515

Schulze, F.E., 1880. Untersuchungen über den Bau und die Entwicklung der Spongien. Neunte Mittheilung. Die Plakinidae. Z. wiss. Zool., 34: 407-450, pls. 20-22.

Stephens, J., 1915. Sponges of the coast of Ireland. 1.-The Triaxonida and part of the Tetraxonida. Fisheries Ireland, Sci. Investigations, 1914, IV [1915]: 1-43.

Topsent, E., 1895. Étude monographique des spongiaires de France. II. Carnosa. Arch. Zool. exp. gén., (3) 3: 492-590.

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