Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fish fins can sense touch

11.02.2016

New study finds pectoral fins feel touch through a surprisingly similar biological mechanism to mammals

The human fingertip is a finely tuned sensory machine, and even slight touches convey a great deal of information about our physical environment. It turns out, some fish use their pectoral fins in pretty much the same way. And do so through a surprisingly similar biological mechanism to mammals -- humans included.


High-speed video of the pictus catfish. Pectoral fins are held at a constant angle to the body throughout the swimming motion, allowing researchers to isolate and study neurons involved in touch sensation.

Credit: University of Chicago

In a study published in the Proceedings of the Royal Society B on Feb. 10, 2016 University of Chicago scientists have shown for the first time that pectoral fins in at least one species of fish possess neurons and cells that are exquisitely sensitive to touch. The discovery not only sheds light on the evolutionary biology of touch, it might also someday inspire new advances in the design of underwater robotics.

"It was a surprise to us that, similar to mammalian skin, fish fins are able to sense light pressure and subtle motion," said study author Adam Hardy, graduate student in the Department of Organismal Biology and Anatomy. "This information seems to be conveyed by a type of cell important for touch in mammals, which suggests that the underlying sensory morphology may be evolutionarily conserved."

... more about:
»Biology »catfish »neurons »pectoral fins

Located just behind the gills, pectoral fins are a pair of distinctive appendages that correspond to forelimbs in four-legged animals. Usually involved in propulsion or balance during swimming, pectoral fins have evolved dramatic functions in certain species. They famously allow flying fish to fly and mudskippers to crawl, for example. Numerous studies have explored the biomechanics, evolution and development of these fins, but little is known about what role they play as a sensory mechanism.

So Hardy, with graduate mentor Melina Hale, PhD, William Rainey Harper Professor of Organismal Biology and Anatomy, asked a simple question: can fish feel with their fins?

There is evidence that fish possess the sense of proprioception, or awareness of where their fins are relative to their bodies (much like how we can tell where our arms are even with our eyes closed). Previous studies have identified fin neurons that send signals containing information about bending, movement and position back to the brain. But touch is distinct from proprioception, and as fins are almost always in motion, teasing apart the two senses in an experimental setting is difficult.

Hardy and Hale approached this challenge by focusing on the pictus catfish, a small, bottom-dwelling species native to the muddy waters of the Amazon river. Aside from a hardened, serrated spine used for defense, the pectoral fins of these fish are fairly typical -- several bony rays connected by a soft membrane. However, pictus catfish don't appear to use their pectoral fins for locomotion, which the team confirmed through high-speed camera analyses.

Without conflicting signals from fin movement and positioning, the researchers were able to isolate and study neural activity in response to touch. They applied a variety of different stimuli with the flat end of a pin and a brush to the pectoral fin, and measured the activity of neurons that are responsible for sending information back to the brain.

The team discovered that neurons not only responded when contact was made, they carried information about the degree of pressure and the motion of the brush as well. An analysis of the cellular structures of the fin revealed the presence of cells that closely resemble Merkel cells, which are associated with nerve endings in the skin of mammals and are essential for touch.

"Like us, fish are able to feel the environment around them with their fins. Touch sensation may allow fish to live in dim environments, using touch to navigate when vision is limited," Hale said. "It raises a lot of exciting questions on how sensory cells shape the brain's perception of environmental features, and may provide insight into the evolution of sensation in vertebrates."

Intriguingly, this discovery could also have applications for underwater robotic design, especially in low-light environments.

"Understanding how membranous fins in fish are used to sense touch helps us identify what features are important for the design of underwater sensory membranes," Hale said. "For example, you can envision fish-inspired sensory membranes that can be used to scan surfaces in underwater environments where light may be obscured."

"In addition, animals use mechanical feedback to help control their limb movements," she adds. "Instrumenting underwater robots with touch sensors may help to improve their performance, particularly when navigating through complex environments."

The team are now studying touch sensitivity in the fins of other species of fish, such as flounders, as well as investigating the precise mechanisms for how fin neurons encode information about touch.

"One of big questions were trying to answer is whether this applies to all fish," Hardy said. "We predicted that touch sensitive fins would be very useful for bottom-dwelling fish, but you can imagine its utility in nocturnal or deep-sea environments as well."

###

The study, "Touch sensation by pectoral fins of the catfish Pimelodus pictus," was supported by the Office of Naval Research and the National Science Foundation. Additional authors include Bailey Steinworth.

Kevin Jiang | EurekAlert!

Further reports about: Biology catfish neurons pectoral fins

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>