Form: Branching erect, branch diameter about 4-6mm, and more or less circular in cross-section. Branches gradually taper to blunt tips. Branching may be very regular and dichotomous; or profusely branched (usually when found in estuarine conditions). Stalked, branches rarely fuse.
Colour: Ochre, yellow/brown.
Smell: None. Slime : None.
Consistency: Firm, "elastic". There is a soft outer layer on a dense axial core. The outer layer is easily rubbed from the inner core.
Surface: Bristly (villose), with hairs of uniform length (cf. Stelligera stuposa). Hairs may trap particles of silt.
Apertures: The small oscules can be seen underwater, and tend to form evenly spaced rows along the edge of branches. Not apparent when preserved.
Skeleton: Plumoreticulate, with a dense axial condensation of reticulating spongin fibres, which are cored by subtylostyles and sparsely echinated by acanthostyles. There is a soft, extra-axial skeleton of long spicules radiating out at right angles from the core to pierce the surface. Divergent brushes of slender spicules surround the projecting spicules at the surface. The spongin becomes more abundant as the animal ages.
Spicules: The megascleres of the axial and extra-axial skeletons are styles or subtylostyles (a,b) 1375-(1575)-1800Ám. The echinating spicules are acanthostyles (d) (70-135Ám, mostly 70-100Ám) (rarely acanthoxea), and are best seen in longitudinal sections (they are rare or very rare in this species, cf. Raspailia ramosa). Divergent brushes are of slender styloids (c) 220-(320)-420Ám). No microscleres.
Habitat: In moderately exposed sites or sheltered sites with some tidal flow. Often with Raspailia ramosa, Stelligera stuposa and other Axinellids in open water. Maybe "on shells and Lithophyllum" (?) - confirmation would be valuable.
Distribution: Widespread; west coasts of British Isles; Irish Sea; "Norway; Belgium; France; Spain; Portugal; Mediterranean."
Distribution Map from NBN: Grid map (fast) : Interactive map (slower, requires login to view records) : National Biodiversity Network mapping facility, data for UK.
Identity: Can be very similar to some individuals of Stelligera stuposa (q.v.), especially in the middle size range (i.e. up to ca. 15cm high). A microscopic examination is always essential for positive identification as there is a considerable overlap between the two species. The only characters which may prove to be reliable are the bristly nature of the surface - evenly bristly in Raspailia, unevenly bristly in Stelligera; and that Raspailia does not produce slime whereas Stelligera does. Raspailia tends to accumulate small particles of silt, whereas Stelligera tends to bind the silt into larger particles, probably because of the slime production (see Table under Stelligera stuposa).
Voucher: BELUM : Mc809. Portrush, Co Antrim.
Editors: D. Moss, B.E. Picton.
|Picton, B.E., Morrow, C.C. & van Soest, R.W.B., 2011. [In] Sponges of Britain and Ireland |
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