Swimming eukaryotic microorganisms exhibit a universal speed distribution

Abstract

One approach to quantifying biological diversity consists of characterizing the statistical distribution of specific properties of a taxonomic group or habitat. Microorganisms living in fluid environments, and for whom motility is key, exploit propulsion resulting from a rich variety of shapes, forms, and swimming strategies. Here, we explore the variability of swimming speed for unicellular eukaryotes based on published data. The data naturally partitions into that from flagellates (with a small number of flagella) and from ciliates (with tens or more). Despite the morphological and size differences between these groups, each of the two probability distributions of swimming speed are accurately represented by log-normal distributions, with good agreement holding even to fourth moments. Scaling of the distributions by a characteristic speed for each data set leads to a collapse onto an apparently universal distribution. These results suggest a universal way for ecological niches to be populated by abundant microorganisms.

Substratum selection and feeding responses influence the demography of the sessile rotifer Cupelopagis vorax (Collothecacea: Atrochidae)

“…However, in the cultures and experiments, swimming speed and behaviour (crawling vs. free‐swimmers) of prey were different among littoral ( Euchlanis , Lecane , Lepadella and Squatinella ) or planktonic rotifers ( Brachionus and Plationus ) and protozoans. Some studies have shown that the swimming speed of littoral rotifers is lower (0.18–0.41 mm s −1 ) than that of bdelloids (0.52–0.54 mm s −1 ), ciliates (0.44–3.16 mm s −1 ), and planktonic rotifers (0.31–0.8 mm s −1 ); however, information on the subject is limited (Colangeli et al, 2018; Lisicki et al, 2019; Preston et al, 1999; Santos‐Medrano et al, 2001).…”

Slip Length Dependent Propulsion Speed of Catalytic Colloidal Swimmers near Walls

“…We fit the corresponding probability density function (PDF) of the velocity with a log-normal distribution following Ref. [24] to obtain the velocity distribution parameters on each substrate. Details on the determination of colloid velocities can be found in SI Section I D. The most frequently encountered velocities, as obtained from the fitted peak position of each PDF, are 1.05 ± 0.09, 1 ± 0.2, and 2.8 ± 0.3 µm/s, above glass, PE, and PDMS, respectively.…”

Frequency-dependent higher-order Stokes singularities near a planar elastic boundary: Implications for the hydrodynamics of an active microswimmer near an elastic interface

“…The sign of the dipolar coefficient α D distinguishes between pusher (α D > 0) and puller (α D < 0) microswimmers. Some bacterial microorganisms, such as E. coli, exploit (bundles of) helical filaments called flagella for their propulsion, the rotation of which causes the entire bacterium to move forward in a corkscrew-like motion [154][155][156] . Here, the translation-rotation coupling of the hydrodynamic friction of the flagellum yields a net propul-sion of the swimmer.…”