Boleophthalmus boddarti is an amphibious gobiid mudskipper which builds and maintains mud-walled polygonal territories on the mudflats of Kuwait. The factors that influence territorial establishment and acquisition were investigated by observation and by the removal of resident fish and/or removal of territorial boundary walls. Smaller replacement fish quickly occupied vacant territories with and without walls, although the latter were sometimes occupied by several small non-territorial or errant individuals. Resettlement patterns (simultaneous or consecutive) had little effect in altering the size or shape of territories. These results are discussed in relation to other fish removal experiments.