In Brazilian reefs, zoanthids, especially Palythoa caribaeorum are fundamental for structuring the local benthic community. The objective of this study was to determine the growth rate of P. caribaeorum, and to assess the influence of the site (different beaches), season (dry and wet), location (intertidal or infralittoral zones), and human pressure associated with tourism. For one year we monitored the cover of P. caribaeorum in transects and focused on 20 colonies. We cut off a square (100 cm 2 ) from the central part of the colony and monitored the bare area for four months in each season. The average growth rates varied from 0.015 and 0.021 cm.day -1 . The rate was homogeneous in all localities, and there was no influence from colony site, location, or touristic visitation, showing that the growth velocity may be an intrinsic characteristic of the species, with a strong genetic component. The growth rate of P. caribaeorum differed among months, and peaked in the first month after injury. The average cover varied from 6.2 to 22.9% and was lower on the reef visited by tourists. The present study corroborates the hypothesis that P. caribaeorum is important for coastal reef dynamics due to its fast and continuous growth.

This is the first record of the starlet sea anemone, Nematostella vectensis Stephenson, 1935, in Southern Hemisphere waters. Specimens of N. vectensis were collected in the surroundings of the Port of Recife, Pernambuco, Brazil. The species is native to the Atlantic coast of the United States of America; populations along the Pacific coast of the USA and the coasts of England are the result of anthropogenic introduction, probably associated with ships and boats used in oyster commerce (Sheader et al. 1997; Pearson et al. 2002; Reitzel et al. 2008). The present study extends the latitudinal distribution of this species, and we discuss the presence on the Brazilian coast of this exotic species.

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