Form: Very thin sheets (less than 1mm?)

Colour: Brown or yellow.

Smell: None?

Consistency: Compact.

Surface: Even, smooth, slightly hispid. Subsurface canal patterns visible in some specimens.

Apertures:

• Not apparent if canal patterns absent.

Contraction:

• Slight, accompanied by closure of canals.

[ More images ]

Synonyms: Alcyonium epiphytum Lamarck, 1816, Suberites epiphytum (Lamarck, 1816) Ridley 1884: 465.

Internal characters

Skeleton: In very thin specimens, the skeleton consists of tylostyles arranged perpendicularly to the substrate, with the heads nearer to the substrate and sometimes touching it. In thicker specimens the basal spicules are overlain by spicule bundles that anastomize and may run either perpendicular or parallel to the substrate. At the surface the spicule bundles usually support projecting tufts of spicules (causing the hispid appearance), but tangential spicules may also be present in the dermal membrane.

Spicules: The megascleres are tylostyles (a,b), usually from about 110-(145)-180 x 4 μm and 220-(300)-350 x 7 μm in a given specimen. However, lengths to ca. 600 μm and widths to ca. 11 μm may occur in some specimens. There is no consistent relation between length and width (width is measured just beneath the head). The shafts are usually curved. The curvature occurs about one quarter to one third the length of the shaft from the head and is sometimes pronounced. The shaft tapers gradually to a sharp point in the distal half to one third of its length. The greatest thickness is just above the head. The head is smooth and shaped like an old-fashioned door handle, weakly mucronate spicules being rare. Thinner spicules often exhibit a smaller additional swelling immediately adjacent to the head. Microscleres are absent.

Identity: A microscopic examination is essential. A combination of spicules orientated perpendicularly to the substrate, door-handle like heads and the other spicule characteristics described above can confirm identity. Reliable field identification characteristics are not yet known.

Distribution Map from NBN: Protosuberites denhartogi at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Protosuberites denhartogi at iNaturalist World Species Observations database.

WoRMS: Protosuberites denhartogi at World Register of Marine Species. Accepted name: Protosuberites denhartogi van Soest & de Kluijver, 2003. AphiaID: 170782.

Classification: Biota; Animalia; Porifera; Demospongiae; Heteroscleromorpha; Suberitida; Suberitidae; Protosuberites

Voucher: BELUM : Mc856. Menai Straits, Wales.

Editors: D. Moss, B.E. Picton.