[EN] A population of hydropolyps epizoic on an Halimeda tuna community, at 12 m depth on an area of the Catalonian coast (NE of Spain), has been studied. A total of 40 thalluses were collected in samples taken between March and July 1985. Thirty-three species of hydropolyps were obtained, belonging mainly to the Haleciidae, Campanulariidae and Lafoeidae families. Their distribution along the H. tuna thallus has been studied, considering three levels: basal, middle and apical. The distribution of each hydropolip species is discussed in terms both of their relative abundance and of five different kinds of strategy, that are defined according to the colonization ability of each species. It is generally observed that the unstability of the algae substratum itself renders the development of both general and specific strategies of the hydropolyps over H. tuna difficult. Moreover, the collected species are also quite common on other kjnds of algal substratum, seagrasses and even artificial substrata. Evidences obtained reaffirm the high colonizing ability of Hydrozoans over al1 kinds of avalailable substratum. This is mainly due to their short lyfe-cycles and other features which are good examples of r strategists

[ES] En las comunidades bentónicas marinas la naturaleza del sustrato es uno de los factores más limitantes en la distribución de las especies. Esta afirmación es aún más importante si se considera la estabilidad del mismo (HARTNOLL, 1983; OSMAN, 1977). [...]

11 pages, 5 figures, 1 table

Peer reviewed