DTU AQUA National Institute of Aquatic Resources
Centre for Ocean Life
Henrik Dams Allé
Building 202, room 4133
2800 Kgs. Lyngby
Request a vCard via e-mail.
On 5 April 2024, Kristian Maar will defend his PhD thesis. The defence can be followed online or attended in person at DTU Lyngby Campus.
From bacteria to whales, this is how the Villum Center for Ocean Life itself describes their range within the scientific approach they launched with the center in 2012. In 2024 it ends. We drawa portrait of the marine research centre, which has focused its attention on the big lines instead of the individual species when looking at life...
The swimming sperm cell reminds us of our aquatic ancestors: the flagellates. While the sperm cell uses its flagellum solely for propulsion, flagellates use their flagellum also for foraging, making them the most important predators on bacteria and picophytoplankton in the ocean. A new review explores the fluid mechanics of predation...
Copepods are among the most common multicellular organisms on earth and feed on a wide variety of prey. When capturing food, they have to briefly handle it before they can ingest it. However, not much is known about how the handling time impact copepod feeding efficiency.
Ecosystems are complex machineries, and our ability to predict how multiple drivers and environmental forcing structure communities are limited. One way to represent and understand organisms, communities and ecosystems is to think in terms of 'traits' rather than species, and how the dominant traits emerge in an evolutionary and ecological...
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...
Diatoms are one of the most diverse groups of phytoplankton in the ocean. One reason for this high diversity is the evolution of multiple defence mechanisms and subsequent evolution of grazer “counter measures”. In a new study, we describe the discovery of yet another defence mechanism: when exposed to chemical cues from copepods several...
Ambush-feeding copepods passively wait for its prey and capture them by a fast surprise attack. The copepods sense the hydromechanical signals generated by their motile prey. However, the ambush feeding copepod Apocyclops royi can be sustained on a diet of Baker’s yeast, which are small, non-motile cells. We asked how this ambush-feeding...
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...
Many species of phytoplankton release toxins that combat competitors and predators. It has long puzzled researchers how such ‘public good’ toxicity has evolved, because mutant ‘cheaters’ that do not pay the cost of toxin production would benefit equally from the toxicity and thus outcompete the toxin producers. In a new study we describe...
In the oceans, a nearly constant biomass of organisms is found in equal log- intervals of body-size. This large-scale regularity is referred to as the size spectrum. In this new modelling study, we find that parameters of the size spectrum correlate strongly with the export and export efficiency of particles into the deep ocean. These...
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...
The deep-sea glass sponge Euplectella aspergillum is well known due to its beautiful lattice-work structure, and has attracted interest in its solid and fluid mechanical properties. In a recent paper, we argue that including sponge tissue is key in understanding the hydrodynamics of these beautiful animals, and an analysis of their hydrodynamics...
The bloom-forming diatom Pseudo-nitzschia produces a potent neurotoxin, domoic acid, that may cause closure of fisheries. The reason for its production has long been under debate. In a new study (in collaboration with the Natural History Museum of Denmark) we demonstrate a ‘private-good’ benefit to producing the toxins as toxic cells...
In a new paper, Ocean Life researchers use direct observations of predator-prey interactions to study the defensive benefit of colony formation in four species of phytoplankton.
Organisms adapt to predation risk by changing their behavior. A new study from the Centre for Ocean Life demonstrates how defensive behaviors of marine pelagic organisms, from phytoplankton to fish, may significantly change the intensity of the biological carbon pump and, hence the ability of the ocean to sequester carbon.
The diatom frustule has been shown to provide protection against grazing copepods, but the mechanisms behind the defense is unknown. In a new paper published in Limnology and Oceanography Letters, we directly observe copepod-diatom interactions and provide a mechanistic understanding of the defense: not only are diatoms with thicker shells...
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...