Halicnemia gallica (Topsent, 1893)


Family : Raspailiidae

Form: Previously known as Halicnemia patera, which is confined to deep water. Shallow water records should be identified as H. gallica. A thin crust (to 2mm thickness) forming discrete rounded patches on rock surfaces.

Colour: Pale orange-pink, yellow, ochre.

Smell: None. Slime: Considerable quantities of slime are released from the sponge on removal from water.

Consistency: Tough, fibrous.

Surface: Conulose with tissue supported on bundles of long spicules which lie at an angle to the surface, facing the same direction and giving a swept appearance.

Apertures: Oscules are small and inconspicuous, not raised above the surface.

Contraction: None noticeable, but collected specimens have a tendency to curl.

Internal characters

Skeleton: A basal layer of large scattered tylostyles lie at an angle to the substratum with their swollen heads lying in contact with the substratum. Long thin centrotylote oxea form dense bundles which ascend at an angle through the sponge to the surface. The entire sponge is filled with a dense mass of small acanthoxea.

Spicules: The large tylostyles (c) measure up to 2mm but are normally broken during preparation. The centrotylote oxea (b) form dense bundles. Acanthoxea (a) have a characteristic sharp bend in the middle of their length.

Habitat: Recent observations of this species in shallow water have been from steep rockfaces with considerable amounts of silt.

Distribution: Old records are from Brittany. Recent finds have been from Roaringwater Bay and Lough Hyne in West Cork, Ireland and from Skomer Island, South Wales.

Distribution Map: NBN map : National Biodiversity Network mapping facility, data for UK.

Identity: The external appearance of the surface combined with the colour makes tentative field identification possible. The spicule compliment is unusual and characteristic.

Voucher: BELUM: Mc1598. Lough Hyne, Co Cork.

Editors: B. E. Picton.

 Picton, B.E., Morrow, C.C. & van Soest, R.W.B., 2011. [In] Sponges of Britain and Ireland