Summary Dispersal is the movement of organisms from one habitat to another that potentially results in gene flow. It is often found to be plastic, allowing organisms to adjust dispersal movements depending on environmental conditions. A fundamental aim in ecology is to understand the determinants underlying dispersal and its plasticity. We utilized 22 strains of the ciliate Tetrahymena thermophila to determine if different phenotypic dispersal strategies co-exist within a species and which mechanisms underlie this variability. We quantified the cell morphologies impacting cell motility and dispersal. Distinct differences in innate cellular morphology and dispersal rates were detected, but no universally utilized combinations of morphological parameters correlate with dispersal. Rather, multiple distinct and plastic morphological changes impact cilia-dependent motility during dispersal, especially in proficient dispersing strains facing challenging environmental conditions. Combining ecology and cell biology experiments, we show that dispersal can be promoted through a panel of plastic motility-associated changes to cell morphology and motile cilia. Graphical abstract Highlights Tetrahymena thermophila exhibits intra-specific diversity in morphology and dispersal. Cell motility behavior during dispersal changes with cilia length and cell shape. Cells from proficient dispersing strains transiently change basal body and cilia position. Starvation-induced dispersal triggers increased basal body and cilia density and caudal cilium formation in rapid-swimming cells.

Plastic cell morphology changes during dispersal