Description: Previously reported as Hexadella racovitzai this species was shown to be a species complex in 2012. Atlantic specimens belong to the new species Hexadella topsenti. (Reveillaud et al., 2012). This sponge looks like a thinly stretched skin extending across rock surfaces. It has a few large oscules with transparent rims, which collapse on disturbance. The colour is usually pink to grey. Patches extend to 20cm or more across. It has no spicules.

Habitat: On steep rock faces and boulders in depths of 20-30m.

Distribution: Hexadella racovitzai is a very similar species occurring in the Mediterranean Sea.

Key Identification Features:

• Fibrous appearance to surface
• Few large oscules

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

iNaturalist: Hexadella topsenti at iNaturalist World Species Observations database.

GBIF data for Hexadella topsenti

WoRMS: Hexadella topsenti at World Register of Marine Species. Accepted name: Hexadella topsenti Reveillaud, Allewaert, Pérez, Vacelet, Banaigs & Vanreusel, 2012. AphiaID: 707474.

Classification: Biota; Animalia; Porifera; Demospongiae; Verongimorpha; Verongiida; Ianthellidae; Hexadella