title: Dancing volvox: hydrodynamic bound states of swimming algae.
abstract: The spherical alga Volvox swims by means of flagella on thousands of surface somatic cells. This geometry and its large size make it a model organism for studying the fluid dynamics of multicellularity. Remarkably, when two nearby Volvox colonies swim close to a solid surface, they attract one another and can form stable bound states in which they "waltz" or "minuet" around each other. A surface-mediated hydrodynamic attraction combined with lubrication forces between spinning, bottom-heavy Volvox explains the formation, stability, and dynamics of the bound states. These phenomena are suggested to underlie observed clustering of Volvox at surfaces.
authors.affiliation: Department of Applied Mathematics, University of Cambridge, Cambridge CB3 0WA, United Kingdom.
authors.forename: Knut
authors.initials: K
authors.lastname: Drescher
authors.forename: Kyriacos C
authors.initials: KC
authors.lastname: Leptos
authors.forename: Idan
authors.initials: I
authors.lastname: Tuval
authors.forename: Takuji
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Pedley
authors.forename: Raymond E
authors.initials: RE
authors.lastname: Goldstein
mesh_terms: D009068:Movement / Q000502:physiology*; D044446:Volvox / Q000166:cytology / Q000502:physiology*; D014867:Water
chemical_list: D014867:Water