The North American comb jellyfish Mnemiopsis leidyi has long been known to consume vast quantities of zooplankton. A few years ago the species became established in Northern Europe.
Like many other jellyfish, Mnemiopsis leidyi has a large gelatinous body. The large size increases its chances of encountering prey, but can also be a disadvantage since the prey organisms are often highly sensitive to movements in the water. Nevertheless, the comb jellyfish manages to catch large amounts of copepod plankton, which are known for their acute escape response.
Able to catch the world’s most vigilant plankton
‘Copepods have a well developed ability to detect even the slightest water disturbance,’ says Lars Johan Hansson, a researcher at the Department of Marine Ecology at the University of Gothenburg. ‘They can swim well clear of the source of water deformation in just a split second. How the comb jellyfish is able to approach and catch some of the animal world’s most vigilant plankton has up until now been unknown.’
The researchers used advanced video technology to study water flows around and within the comb jellyfish. These measurements were then used to calculate the water deformation generated by the jellyfish and compare this with the levels that trigger an escape response in copepods.
‘It emerged that the comb jellyfish uses microscopic, hairlike cilia inside its oral lobes to generate a feeding current that carefully transports water between the lobes. As the water accelerates slowly and is transported undisturbed into the jellyfish together with the prey, there is nothing that alarms the prey until it is next to the capture site inside the lobes, by which time it’s too late to escape. This makes the jellyfish a hydrodynamically silent predator.’
The research on the ability of the comb jellyfish to capture its prey was carried out jointly by researchers from the USA, Norway and the Department of Marine Ecology at the University of Gothenburg.
The study – Stealth predation and the predatory success of the invasive ctenophore Mnemiopsis leidyi – has been published in the scientific journal PNAS.Contact: Lars Johan Hansson
Helena Aaberg | idw
To proliferate or not to proliferate
21.03.2019 | Max-Planck-Institut für molekulare Zellbiologie und Genetik
Discovery of a Primordial Metabolism in Microbes
21.03.2019 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.
The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...
Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.
Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...
The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.
A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...
Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.
"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...
New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum
For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...
11.03.2019 | Event News
01.03.2019 | Event News
28.02.2019 | Event News
21.03.2019 | Life Sciences
21.03.2019 | Physics and Astronomy
21.03.2019 | HANNOVER MESSE