Ciocalypta penicillus forms an encrusting cushion, usually about 10 cm in diameter, with a rough upper surface. Firm, but flexible, pointed, conical projections or digits grow upwards from the base. These projections are about 5 cm high and 0.5 cm wide. The cushions are brownish or whitish-yellow in colour, while the digits are usually translucent.The basal cushion is often covered by sand or gravel so only the digits are visible.

The form of this sponge is very characteristic, it consists of a basal cushion buried in sand or gravel, from which project large conical, translucent papillae. The surface of the papillae has a glassy, translucent appearance, through which vertical spicule fibres can be seen. A central core runs the length of the papillae, this is usually conspicuous in living material. The walls of the papillae are thick and robust with a roughened texture. May be confused with Polymastia species, especially Polymastia penicillus. However, large conical papillae with a translucent, glassy appearance and visible central core are characteristic of Ciocalypta.

Atlantic Europe, Australia, Azores Canaries Madeira, Azores Exclusive Economic Zone, Belgian Exclusive Economic Zone, Cape Verde, Celtic Seas, European waters (ERMS scope), Gulf of Guinea West, Indian Ocean, Indonesian Exclusive Economic Zone, Irish Exclusive economic Zone, Levantine Sea, Malaysia, Maldives, Mediterranean Sea, Natal, New Zealand Exclusive Economic Zone, North East Atlantic, Red Sea, Saldanha Bay, South Africa (country), United Kingdom Exclusive Economic Zone, West Africa, Wimereux

Known recently from scattered localities on the western coasts of the British Isles.

Depth range based on 32 specimens in 1 taxon.
Water temperature and chemistry ranges based on 6 samples.

Environmental ranges
  Depth range (m): 0 - 49
  Temperature range (°C): 10.625 - 23.797
  Nitrate (umol/L): 0.484 - 7.489
  Salinity (PPS): 35.229 - 35.982
  Oxygen (ml/l): 4.813 - 6.192
  Phosphate (umol/l): 0.119 - 0.539
  Silicate (umol/l): 1.193 - 2.878

Graphical representation

Depth range (m): 0 - 49

Temperature range (°C): 10.625 - 23.797

Nitrate (umol/L): 0.484 - 7.489

Salinity (PPS): 35.229 - 35.982

Oxygen (ml/l): 4.813 - 6.192

Phosphate (umol/l): 0.119 - 0.539

Silicate (umol/l): 1.193 - 2.878
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

 Ciocalypta penicillus is usually found attached to upward facing rock surfaces typically covered in clean sand or gravel but sometimes more silty sediment.

This species is very characteristic of, and appears to be restricted to bedrock/sediment interfaces, where upward facing bedrock or large boulders are overlain by clean coarse sand or gravel. It is usually found in the circalittoral zone in areas exposed to moderately strong wave action or tidal streams.