Microciona fallax Bowerbank, 1866


Family : Microcionidae

Form: Thin sheet or cushion covering rock in patches to 15cm or more in diameter.

Colour: Red to reddish-orange.

Smell: ?

Consistency: Crumbly.

Surface: Bumpy-rough. Excurrent channels may be obvious.

Apertures: The oscules are fairly regularly distributed and reasonably obvious because of the presence of converging channels.

Contraction: Some, especially of the oscules.

Internal characters

Skeleton: Typical Microciona with plumose columns of large, nearly smooth, acanthostyles echinated by smaller, entirely-spined acanthostyles. There is a surface layer of subtylostyles and very abundant minute chelae. Toxa may be rare and not present in all specimens. Fine flexuous subtylostyles may be common, scattered throughout the tissue.

Spicules: Spiculation is similar to that of Microciona spinarcus. The toxa taper to points and are sparsely spined near their ends.

Habitat: On vertical rock faces in exposed places with strong wave action or tidal streams.

Distribution: Known from the south and west coasts of Ireland: Saltee Is., Co. Wexford; Sherkin Is., Co. Cork; Rathlin O'Birne Is., Co. Donegal.

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

Identity: This sponge is very similar to M. spinarcus (q.v.). The presence of flexuous subtylostyles and scarce microspined toxa seems to be characteristic. This, combined with the bumpy surface, may be diagnostic.

Voucher: BELUM : Mc1763. Calf, Isle of Man.

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

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