Acanthodoris pilosa is easy to distinguish from other nudibranch by its rounded, fluffy, soft-textured appearance. It has long, soft, pointed processes (papillae) all over its back, which are usually of a uniform length and colour. Colour is uniformly distributed and varies from white to brown and purplish-brown to charcoal grey. This sea slug usually grows up to 3 cm in length but may exceptionally reach 7 cm. Juveniles may have a speckled appearance. Two horn-like processes (rhinophores) at the front of the animal characteristically bend towards the rear and are much larger than the other processes (papillae). Up to 9 large gills form a circle at the rear of the animal.Feeds on encrusting bryozoans such as Alcyonidium hirsutum and Flustrellidra hispida.

A. pilosa is easily distinguished from other British nudibranchs by its overall 'fluffy' appearance, caused by the presence of long, soft papillae all over the back of the animal. The rhinophores are long, with long shafts below the lamellate portions; the gills are large and fluffy. Colour is variable from white through brown and purple to black. Mature specimens of A. pilosa are usually 30mm in length but may reach almost 70mm. The large rhinophores and the long, soft papillae distinguish this species from any other British nudibranch.

Atlantic, Beaufort Sea, Belgian Exclusive Economic Zone, Brier Island, British Isles, Canadian part of the Arctic Ocean, Cobscook Bay, De Haan, European waters (ERMS scope), Greek Exclusive Economic Zone, Gulf of Maine, Irish Exclusive economic Zone, North West Atlantic, Oostduinkerke, Oostende, Oosterschelde, Portuguese Exclusive Economic Zone, Spanish Exclusive Economic Zone, United Kingdom Exclusive Economic Zone, USA, Wadden Sea, Wimereux, Zeeland

Bay of Fundy shore of Nova Scotia to Virginia

Arctic Seas to Ocean City, Maryland

Common all around the British Isles and from NE America to the Mediterranean.

infralittoral of the Gulf and estuary

Known from rocky shores.

Depth range based on 75 specimens in 1 taxon.
Water temperature and chemistry ranges based on 8 samples.

Environmental ranges
  Depth range (m): 0 - 61
  Temperature range (°C): 7.867 - 11.855
  Nitrate (umol/L): 4.066 - 7.251
  Salinity (PPS): 33.852 - 35.271
  Oxygen (ml/l): 5.743 - 6.234
  Phosphate (umol/l): 0.418 - 0.605
  Silicate (umol/l): 2.512 - 4.451

Graphical representation

Depth range (m): 0 - 61

Temperature range (°C): 7.867 - 11.855

Nitrate (umol/L): 4.066 - 7.251

Salinity (PPS): 33.852 - 35.271

Oxygen (ml/l): 5.743 - 6.234

Phosphate (umol/l): 0.418 - 0.605

Silicate (umol/l): 2.512 - 4.451
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

 Acanthodoris pilosa is often found on the shore but has also been recorded to depths of 80 m.

The prey of A. pilosa consists of encrusting bryozoans such as Alcyonidium hirsutum and Flustrellidra hispida on shore and the erect fleshy bryozoan Alcyonidium diaphanum in the sublittoral.

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There is 1 barcode sequence available from BOLD and GenBank.   Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen.  Other sequences that do not yet meet barcode criteria may also be available.


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Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 5
Species With Barcodes: 1