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Studying the population dynamics of the surf clams Donax hanleyanus and Mesodesma mactroides from exposed sandy beaches off Argentina, there were found differences in the spatial and temporal scale of the population structure, growth and reproduction biology of this two dominant species. Histological analyses on three Argentinean sandy beaches with contrasting morphodynamics not only revealed the size at first maturity and a distinct reproductive cycle compared with historical data, but also negated the habitat harshness hypothesis which was commonly used for sandy beach communities. Furthermore, realizing fluorescent tagging-recapture experiments, a new time saving method to estimate growth was developed.

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The author studied at FU-Berlin and graduated at IFM-GEOMARKiel working on benthic communities of Svalbard. Afterwards herealized the present doctor thesis at University of Buenos Airesand the Argentine Museum of Natural Science cooperating with theAlfred Wegener Institute. Lately he is researching at Labomar,Universidade Federal do Ceará.

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