Pachymatisma johnstonia (Bowerbank, 1842)

Pachymatisma johnstonia

Description: This sponge may be massive-lobose, hemispherical to irregularly rounded and up to 30cm or more across. It is usually grey to off-white in colour but may be completely white in dark caves. Rounded evenly spaced oscules are obvious all along the tops of the ridges.

Habitat: Common on bedrock and stable boulders from the littoral to 300m. A common species in sites with strong water movement, but also found under overhangs in extreme shelter.

Distribution: A common species throughout most of the British Isles but apparently absent from North sea coasts.

Similar Species: Unlikely to be confused with other species.

Key Identification Features:

Distribution Map from BioMar data for Ireland - Google Earth map:  download this placemark (not got Google Earth installed?)

Distribution Map from NBN: Grid map (fast) : Interactive map (slow, requires login to view records) : National Biodiversity Network mapping facility, data for UK.

 Picton, B.E. & Morrow, C.C. (2015). Pachymatisma johnstonia (Bowerbank, 1842). [In] Encyclopedia of Marine Life of Britain and Ireland.
http://www.habitas.org.uk/marinelife/species.asp?item=C1670 Accessed on 2015-10-9

[Show species list]