Bugula stolonifera is an erect bryozoan that is mainly found on submerged structures in ports and harbours. The colonies are composed of greyish-buff dichotomous branches, arranged in a short dense compacted tuft, 3 – 4 cm high. Growth occurs via stolons spreading from the original point of settlement; secondary colonies arise from the stolons. The colonies lack the spiral branching patterns of superficially similar species such as B. avicularia, B. plumosa and B. turbinata. Autozooids are long and slender, typically 0.6 – 0.7 by 0.1 – 0.3 with two spines.
The species settles between June and October, or from April where water has been artificially warmed. It colonises hard substrates, typically submerged structures in marinas. It is distributed throughout the Atlantic and in the Mediterranean. Thought to be non-native in western Europe. It is known from Harwich (east coast of England), Swansea, Milford Have, Neyland and Cobh, Plymouth. Bugula stolonifera is also known from Venice Lagoon, where it tolerates reduced salinities and polluted waters, with low velocity currents.