An exploratory study on grapsid crab zonation in Kenyan mangroves 1, 1 2 3 4 1 F. Dahdouh-Guebas ∗, M. Verneirt , S. Cannicci , J.G. Kairo , J.F. Tack & N. Koedam 1Laboratory of General Botany and Nature Management, Mangrove Management Group, Vrije Universiteit Brus- sel (VUB), Pleinlaan 2, B-1050 Brussels, Belgium; 2Dipartimento di Biologia Animale e Genetica ‘Leo Pardi’, Universita` degli Studi di Firenze, Via Romana 17, I-50125 Firenze, Italia; 3Kenya Marine and Fisheries Research Institute, PO Box 81651, Mombasa, Kenya; 4Belgian Biodiversity Platform, c/o Institute of Nature Conservation, Kliniekstraat 25, B-1070 Brussels, Belgium; ∗Author for correspondence: Tel: +32 02 629 34 22, Fax: 34 13, E-mail:
[email protected] Key words: crab, Detrended Correspondence Analysis, Grapsidae, Kenya, mangrove, zonation Abstract Despite earlier efforts to understand the role played by grapsid crabs in mangroves, their importance in the struc- turing and functioning of such systems is fully appreciated, particularly with regard to small-scale studies. The present study provides some new data on the interaction between mangroves and crabs, namely the link between the distribution of particular mangrove tree species and the distribution of certain crab species at the assemblage level. Floristic and faunistic relevés were made in Gazi Bay (2 sites) and Mida Creek (3 sites), 140 km apart on the Kenyan coast, along five transects in a series of quadrats covering the width of the mangrove belts. Zonation of both mangrove vegetation and brachyuran fauna was described and height above datum and distance to the mainland (limit of non-flooded area) measured.