Concave A-L interface favours Wrinkly Spreader fitness. Microcosms with concave- (normal) and convex-shaped A-L interfaces were used to assess the importance of the meniscus trap in WS fitness. Microcosms were incubated for 1 or 3 days before assay and the relative competitive fitness of the Wrinkly Spreader was determined compared to the non-biofilm-forming P. fluorescens SBW25. Here, the relative fitness () is provided where the reference microcosms with a concave-shaped A-L interface have relative fitness of one (marked by the horizontal dashed line); the curve indicated here is illustrative only. Means ± SE are shown () and means not linked by the same letter are significantly different (TK-HSD, ).