LoadingText

News from DTU

2022
25 OCT

Using Ultrasound to Tether Microorganisms

Swimming microorganisms move as they please, and it requires patience to observe their appendage motions, swimming kinematics, and the resulting flows. In a new paper in the Journal of Experimental Biology, we show how to use ultrasound to acoustically tether and enable behavioral observations of individual microorganisms with simple...

14 JUL

Hairy flagellates have a clever way to overcome limitations of life at small scales

Flagellates live in a small-scale environment where viscosity impedes contact with their bacterial prey. Most flagellates use the active waving motion of a flexible flagellum with hairs to generate a feeding current. The presence of hairs significantly increases the force generated by the flagellum and also reverses its direction, hence...

Mechanisms and fluid dynamics of foraging in heterotrophic nanoflagellates
29 APR

How do flagellates feed: Mystery solved

Despite living in a micro-scale world governed by viscosity, heterotrophic nanoflagellates are able to clear great volumes of water for prey by creating feeding flows with their flagellum. A new study from the Centre describes how flagellates with different feeding strategies overcome the impeding effect of viscosity, and provides a mechanistic...

08 FEB

Feeding flow and membranelle filtration in ciliates

The feeding on suspended food particles in ciliates is complex and relies typically on coordinated motion in bands of transversal rows of cilia known as membranelles. A new paper in Physical Review Fluids explores and models the fluid dynamics of feeding flow and particle retention in ciliates that use a single membranelle band to both...

2021
24 FEB

Ambient flows and feeding currents of sessile suspension feeders

Sessile suspension feeders live attached to surfaces and rely on self-generated feeding currents to bring in suspended prey. A new study published in Journal of the Royal Society Interface combines experiments on the sessile ciliate Vorticella convallaria and fluid dynamical calculations to quantify the influence of ambient flows on the...

04 JAN

Feeding flows of microorganisms attached to solid surfaces

Many aquatic microorganisms attach to solid surfaces while creating feeding flows that bring prey particles to them. A new paper in Physical Review Fluids explores how such feeding flows are affected by the proximity to the surface and the orientation of the flow-generating force.

2020
Tethered flagellates
17 NOV

To tether or not to tether

Many or most flagellates are tethered to particles when feeding, and it is generally accepted that attachment allows organisms to enhance their feeding flow. This view is challenged in a new paper in PNAS where it is shown that the opposite holds true, i.e., the clearance rate is highest for freely swimming organisms in comparison with...

2019
Planktonic encounter rates with non-spherical encounter zones
01 AUG

Planktonic encounter rates with non-spherical encounter zones

A new theoretical approach makes it possible to model planktonic predator-prey interactions and quantify the effects of the encounter zone shape for both non-motile and motile predators.

Dense dwarfs versus gelatinous giants
13 JUN

Dense dwarfs versus gelatinous giants

A new theoretical model describes the trade-offs and physiological limits determining the body plan of planktonic filter feeders and explains why gelatinous plankton are gelatinous.

Flagellates
10 JAN

Why are some flagellates living in a ribbon case?

Choanoflagellates are filter feeders and an important component of microbial foodwebs. Because they are theancestors of multicellular life, they have been intensely studied. Some species build an elaborate external ribbon structure. Its function is unknown but we demonstrate that it may significantly increase prey capture efficiency...

2017
Morphology
15 AUG

New paper: Hydrodynamics of microbial filter feeding

What physical constraints govern microbial filter feeding, and what can we derive about the microbial filter feeder as a trait?

An analytical model of flagellate hydrodynamics
13 MAR

New paper on an analytical model of flagellate hydrodynamics

We present an analytical model framework with which we can predict near-cell flows and trajectories of freely swimming unicellular organisms that swim with different numbers, arrangements, and beat patterns of their flagellar appendages.

Swimming and feeding of mixotrophic biflagellates
31 JAN

New paper on swimming and feeding of mixotrophic biflagellates

Imagine you are a microscopic cell with two thin “arms” and want to survive in the ocean. How should you arrange and move those appendages to swim fast and efficiently, to avoid predators, and to get enough food?

2015
 Planktonic breast stroke swimmers. (a) Chlamydomonas reinhardtii, a flagellate (image by courtesy of Knut Drescher), (b) Mesodinium rubrum, a ciliate, (c) a nauplius (juvenile) of Acartia tonsa, a copepod, and (d) Podon intermedius, a cladoceran.
23 APR

New paper in Physical Review E on “Quiet swimming at low Reynolds number” by Anders Andersen, Navish Wadhwa, and Thomas...

What does it take for plankton to master stealthy swimming, and why are some breast stroke swimming plankton quiet swimmers? New study addresses these questions using a simple model.

https://www.tkboe.aqua.dtu.dk/publications/person?id=6547&tab=7
1 JULY 2025