Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Salamanders chew with their palate

22.03.2019

Zoology research team from the Universities of Jena (Germany) and Massachusetts (USA) discovers potentially primeval chewing behaviour in salamandrids

The Italian Crested Newt – ‘Triturus carnifex’ – eats anything and everything it can overpower. Earthworms, mosquito larvae and water fleas are on its menu, but also snails, small fish and even its own offspring. A research team led by Dr Egon Heiss of Friedrich Schiller University in Jena (Germany) has studied the newt’s chewing behaviour and has made an astounding discovery.


When the Italian Crested Newt (Triturus carnifex) eats the grub, it chews it with its palatal teeth.

(Image: Jan-Peter Kasper/FSU)


Dr Egon Heiss from Jena University with an Italian Crested Newt (Triturus carnifex), whose chewing behaviour was examined.

(Image: Jan-Peter Kasper/FSU)

‘Triturus carnifex’ is an amphibian of the order Caudata and is a true salamander. “According to the textbooks, amphibians swallow their prey whole, but we have been able to refute this,” says Heiss.

Together with doctoral student Daniel Schwarz and Dr Nicolai Konow of the University of Massachusetts, Heiss has succeeded in proving that the crested newts do actually chew their prey, but in a way that is different from that of most other land-based vertebrates. The researchers have now presented their findings in the specialist publication ‘Journal of Experimental Biology’ (doi:10.1242/jeb.189886).

Palatal teeth kill prey

“This newt uses what are called its palatal teeth to kill its prey and also to break it up,” explains Heiss. This means that the jaw teeth are mainly used to catch or hold the prey. With the help of the tongue, the prey is then rubbed rhythmically against the palate. The palate is equipped with very sharp teeth, around 0.5 to one millimetre long, which are constantly replaced by new teeth. These teeth can, for example, tear open the extremely tough cuticula of fly maggots.

“This kills the prey and, at the same time, helps the digestive secretions to take effect,” says Heiss. For the newt, this is also a form of life insurance: some insect larvae have such a strong bite that they would be able to bore through the predator’s body. The first impetus for the surprising research result came on a research visit to Antwerp (Belgium), when Nicolai Konow and Egon Heiss observed a newt feeding.

The biologists were intrigued by the amphibian’s head, jaw and tongue movements after it had seized its prey. “The newt actually appeared to be chewing,” says Heiss. The researchers were able to obtain a clear idea of what was happening with the help of the X-ray video unit at the Institute of Zoology and Evolutionary Research of the University of Jena.

Salamanders chew like primeval land-based vertebrates

The newt’s chewing behaviour prompts the question of how it can be explained in the context of evolution. “We can assume that real palatal teeth were present in early land vertebrates, and we suspect that the ‘tongue against palate’ chewing mechanism, as seen in newts, is something that goes back to the early days of land-based vertebrates,” says Heiss. Very similar chewing mechanisms can indeed be found in ancient mammals such as the echidna and the duckbilled platypus, but also in the manatee. Although in these animals the palatal teeth have been replaced by rough keratin structures, the creatures still rub their food against the palate.

The tongue originated when vertebrates came onto land

From the point of view of evolution, the move from water to land brought about change in animals’ chewing apparatus. A key role is played by the tongue, which only developed after vertebrates left the water. It is crucial for enabling chewing, as it moves food to the right place in the mouth. “With fish, the water current helps to do this,” explains Heiss. A similar change occurs in amphibian larvae; during metamorphosis, the gills of amphibians transform into a tongue when the larvae leave the water.

The findings now presented are the first results from the research project ‘Form, Function and Evolution of Food Manipulation in Urodela’, which is funded by the German Research Foundation (DFG) and was launched at the beginning of 2017. The project runs until the end of 2019 and maybe during that time, ‘Triturus carnifex’ will be persuaded to reveal more secrets.

Wissenschaftliche Ansprechpartner:

Dr Egon Heiss
Institute of Zoology and Evolutionary Research of Friedrich Schiller University, Jena
Erbertstraße 1, 07743 Jena
Germany
Phone: +49 (0)3641 / 949183
E-mail: egon.heiss[at]uni-jena.de

Originalpublikation:

Heiss, E., Schwarz, D., and Konow, N. (2019). Chewing or not? Intraoral food processing in a salamandrid newt. J. Exp. Biol. 222, doi: 10.1242/jeb.189886, http://jeb.biologists.org/content/222/6/jeb189886

Stephan Laudien | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-jena.de/

Further reports about: Salamander Zoology amphibian mosquito larvae palate teeth vertebrates

More articles from Life Sciences:

nachricht Tracing the evolution of vision
23.08.2019 | University of Göttingen

nachricht Caffeine does not influence stingless bees
23.08.2019 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Hamburg and Kiel researchers observe spontaneous occurrence of skyrmions in atomically thin cobalt films

Since their experimental discovery, magnetic skyrmions - tiny magnetic knots - have moved into the focus of research. Scientists from Hamburg and Kiel have now been able to show that individual magnetic skyrmions with a diameter of only a few nanometres can be stabilised in magnetic metal films even without an external magnetic field. They report on their discovery in the journal Nature Communications.

The existence of magnetic skyrmions as particle-like objects was predicted 30 years ago by theoretical physicists, but could only be proven experimentally in...

Im Focus: Physicists create world's smallest engine

Theoretical physicists at Trinity College Dublin are among an international collaboration that has built the world's smallest engine - which, as a single calcium ion, is approximately ten billion times smaller than a car engine.

Work performed by Professor John Goold's QuSys group in Trinity's School of Physics describes the science behind this tiny motor.

Im Focus: Quantum computers to become portable

Together with the University of Innsbruck, the ETH Zurich and Interactive Fully Electrical Vehicles SRL, Infineon Austria is researching specific questions on the commercial use of quantum computers. With new innovations in design and manufacturing, the partners from universities and industry want to develop affordable components for quantum computers.

Ion traps have proven to be a very successful technology for the control and manipulation of quantum particles. Today, they form the heart of the first...

Im Focus: Towards an 'orrery' for quantum gauge theory

Experimental progress towards engineering quantized gauge fields coupled to ultracold matter promises a versatile platform to tackle problems ranging from condensed-matter to high-energy physics

The interaction between fields and matter is a recurring theme throughout physics. Classical cases such as the trajectories of one celestial body moving in the...

Im Focus: A miniature stretchable pump for the next generation of soft robots

Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.

Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The power of thought – the key to success: CYBATHLON BCI Series 2019

16.08.2019 | Event News

4th Hybrid Materials and Structures 2020 28 - 29 April 2020, Karlsruhe, Germany

14.08.2019 | Event News

What will the digital city of the future look like? City Science Summit on 1st and 2nd October 2019 in Hamburg

12.08.2019 | Event News

 
Latest News

Making small intestine endoscopy faster with a pill-sized high-tech camera

23.08.2019 | Medical Engineering

More reliable operation offshore wind farms

23.08.2019 | Power and Electrical Engineering

Tracing the evolution of vision

23.08.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>