Costa, Ana C.Jones, Malcolm B.2011-01-182011-01-182000COSTA, A. C. & M. B. JONES, (2000). The genus Tesseropora (Cirripedia: Tetraclitidae) from São Miguel, Azores. “Arquipélago, Life and Marine Sciences”, Supl. 2(A): 71-78.0873-4704http://hdl.handle.net/10400.3/828Fauna and Flora of the Atlantic Islands : Proceedings of the 3rd Symposium, Ponta Delgada, 21-25-September 1998.The barnaele Tesseropora was considered as primarily an insular Indo-Pacific genus until Tesseropora atlantica was described from Bermuda and the Azores (S. Jorge). T. atlantica has also been recorded from Saint Paul's rocks (equatorial Atlantic), confirming its link with isolated oceanic islands. Recently, another Tesseropora, Tesseropora arnoldi, was described as an Azorean endemic, but as there is some doubt as to the validity of this species, we continue to refer to Azores Tesseropora as T. atlantica. Little is known of the biology of this ancient genus recorded from the Italian Oligocene. In this paper, we report on the habitat, distribution and several population parameters (relative abundance, density and size structure) of Tesseropora atlantica from a boulder beach at Cerco da Caloura, S. Miguel. On this shore, Tesseropora has a patchy distribution and is found bellow the upper limit of Chthamalus stellatus. Clump densities of T. atlantica varied between 37-66, however, nearest neighbour values indicated a rather random distribution within each patch. In addition, the morphology of external plates, examined using scanning electron microscopy, showed some differences compared with published illustrations for the two Atlantic species.engCerco da Caloura (Azores)Genus Tesseropora (Cirripedia: Tetraclitidae)São Miguel Island (Azores)journal article