Cellaria sinuosa (Hassall, 1840)

Cellaria sinuosa is an erect bryozoan that forms dense tufts. The colony is composed of dichotomous branches which have very apparent chitinous joints. Tufts are white in colour and commonly between 4 – 5 cm, but may be up to 10 cm. They are anchored to the substrate via chitinous rootlets.

The internodes are long, thick and cylindrical. They becomes club-shape towards the tips of the colony. The internodes vary in length, but are frequently 4 – 10 mm and 0.4 – 1.6 mm in diameter, making C. sinuosa the stoutest of the three British Cellaria species. Autozooids are hexagonal and average 0.5 by 0.25 mm..

The species is able to colonise stones, as well as a range of other substrates in subtidal waters. It appears able to live in sedimentary areas where the founding zooid will attach to coarse fragments. The depth range of C. sinuosa is uncertain, but it is known to occur at depths of 80 -100 metres in the Mediterranean. Washed-up colonies are often found among strandline debris.

Cellaria sinuosa is distributed in the eastern Atlantic from Shetland to Spain. It occurs in the Mediterranean and off the majority of British coasts. Differentiating between Cellaria species is difficult and C. sinuosa is frequently mistaken for C. fistulosa