  We study the stochastic hydrodynamics of colonies of flagellated swimming
cells, typified by multicellular choanoflagellates, which can form both rosette
and chainlike shapes. The objective is to link cell-scale dynamics to
colony-scale dynamics for various colonial morphologies. Via autoregressive
stochastic models for the cycle-averaged flagellar force dynamics and
statistical models for demographic cell-to-cell variability in flagellar
properties and placement, we derive effective transport properties of the
colonies, including cell-to-cell variability. We provide the most quantitative
detail on disclike geometries to model rosettes, but also present formulas for
the dynamics of general planar colony morphologies, which includes planar
chain-like configurations.
