Description: A small creeping alga, mosslike, very dark brownish-purple, irregularly branched growing from a discoid holdfast to about 2 cms long. Irregularly constricted and with secondary haptera which attach to the surface.

Habitat: Common on rocks in the upper littoral in sheltered places. In exposed shores as an under-growth to Pelvetia and Fucus spiralis.

Distribution: Widely distributed in the British Isles including the Shetland Isles on sheltered shores. Europe: Mediterranean, Azores, Portugal, Atlantic coasts of Spain and France, Netherlands, Norway and Iceland. Further afield: Florida, Bermuda, West Indies, Canary Islands, Morocco also the Pacific and Indian Oceans.

Key Identification Features:

• Irregulary branched with constrictions. Upper shore.

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

iNaturalist: Catenella caespitosa at iNaturalist World Species Observations database.

WoRMS: Catenella caespitosa at World Register of Marine Species. Accepted name: Catenella caespitosa (Withering) L.M.Irvine, 1976. AphiaID: 145605.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Gigartinales; Caulacanthaceae; Catenella