The rediscovery of Cervera atlantica (Johnson, 1861) (Cnidaria: Octocorallia): notes on its identification, ecology and geographical distribution

Cervera atlantica, a small stoloniferan octocoral, was described as Cornularia atlantica by James Yate Johnson in 1861 from Funchal, Madeira. It then remained unrecognized until 1972 when I discovered it on the Mediterranean coast of Spain. I have since confirmed its existence at the type locality and have traced its distribution around Madeira, throughout the Canary Islands, and on Portuguese and English coasts. In the Mediterranean Sea, I have found it along Spanish and French coasts, among the Balearic Islands and on the coast of Cyprus. Cervera atlantica is cryptic and photophobic, living under stones in shallow water (usually at 0-2 m) or in crevices and caves in massive intertidal rocks, protected from direct sunlight. Intolerant of rough water, it usually occurs in sheltered bays, on beaches protected by reefs, or in the lee of headlands. In common with Cornularia cornucopiae, it occurs throughout the Mediterranean, but only very rarely in the same habitat. There may have been confusion between these two species for many years, as Cervera atlantica is apparently rather more common than Cornularia cornucopiae, which hitherto has been generally regarded as the only non-scleritic stoloniferan existing in the Mediterranean. In the Atlantic, Cervera atlantica has a Lusitanian-Mauritanian distribution, occurring both north and south of the Strait of Gibraltar, although its limits are not yet known. Records of Cornularia cornucopiae in the Atlantic are rather rare, only to the north of Gibraltar. In view of the potential confusion with Cervera atlantica, those records need to be confirmed.