Scientists Discover How Fish Evolved To Float At Different Sea Depths
Scientists at the University of Liverpool have discovered how fish have evolved over the last 400 million years to stay motionless at different water depths.
A research team led by Dr Michael Berenbrink, a Comparative Physiologist at the School of Biological Sciences, has revealed how modern fish, such as pike and cod, have developed a way of floating at certain water levels using a gas-filled swimbladder.
Dr Berenbrink investigated the mechanism that allows fishes to keep the swimbladder inflated with gas even at great water pressure in the depths of the sea. The mechanism comprises of a complex system of arteries and veins, called the rete mirabile, and special blood proteins, which can release oxygen even at high oxygen concentrations.
These systems drive oxygen from the blood into the swimbladder allowing the fish to float at different levels in the sea without coming to the surface of the water for air. A similar system is also present in the eye of the fish, which provides oxygen to the retina.
Dr Berenbrink explains: “I am interested in how the mechanisms in the swimbladder and eye could have evolved. Some fish have no swimbladder and others fill it by swallowing air at the surface of the water. Another group of fishes has a closed swimbladder that is inflated through gas secretion even when they are in high water pressures. My aim was to find out how these systems came into place and how this allowed for the great variety of fishes we have in our oceans today."
The study revealed that the special blood proteins, which are essential for oxygen secretion, were present in the eye system 250 million years ago. This predated the swimbladder system by 100 million years. The special blood proteins induced development of the swimbladder system.
Dr Berenbrink continued: “Many researchers believe that the swimbladder evolved from a primitive lung, which can be traced back 400 million years. These findings will help us to understand the diversity and success of modern fishes in their environment.”
Dr Berenbrink’s research will be published in Science magazine on Friday, 18 March 2005.
Samantha Martin | alfa
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
Physicists in Garching observe novel quantum effect that limits the number of emitted photons.
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...