Populations of the spirorbid Pileolaria berkeleyana ( = P. rosepigmentata) are recorded in harbours at Plymouth, Falmouth and Portsmouth and of three similarly abundant serpulids, Filogranula calyculata and Metavermilia multicristata at Abereiddy and Vermiliopsis striaticeps at Falmouth. Ship-borne introductions may well have occurred but the Abereiddy serpulids have more probably come from undiscovered populations nearby, in areas too rocky and deep for easy sampling.
Three apparently exotic species of tubeworms, a spirorbid and two serpulids, have been established for at least five years in aquarium tanks at the Portsmouth Polytechnic Marine Laboratory. The tanks receive a continuous flow of unfiltered sea water, which is pumped from Langstone Harbour via a header tank, with little if any change in temperature. They contain many slate slabs from a flooded quarry (at Abereiddy, in South Wales), which had been opened to the sea in 1932 and is used as a harbour for small boats. The most recent transfer of slates to Portsmouth was in 1972. The slates were brought in because they bore populations of a native spirorbid (Thorp, 1975), but the associated fauna was not closely studied at that time because a general account of Abereiddy quarry and its fauna was being prepared by Hiscock & Hoare (1975).
The exotic serpulids occurred particularly on the undersides of the slates, but had not been noted by Hiscock & Hoare, nor in any other British fauna list. They also occurred on the underside of a disused heater/cooler plate supporting the slates in one of the tanks, which indicated that they had been breeding in that tank.