Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Special skin keeps fish species alive on land

09.11.2010
A new study shows how an amphibious fish stays alive for up to two months on land. It's all in the skin.

Mangrove killifish are small fish—only about an inch or two long—that live in temporary pools in the coastal mangrove forests of Central and South America and Florida. During dry seasons when their pools disappear, the fish hole up in leaf litter or hollow logs.

As long as they stay moist, they can survive for extended periods out of water by breathing air through their skin. But oxygen isn't the only thing a fish out of water needs to worry about, according to Professor Patricia Wright, a biologist from the University of Guelph, Ontario, who has studied these fish for years.

"All cells in the body need the right combination of ions and water for an animal to stay alive," Wright explains. "Normally, the gills are responsible for these processes in fish. We knew that in mangrove killifish the gills are likely useless on land, so how these fish maintain ion balance out of water was a mystery."

Wright's latest research, published in the November/December 2010 issue of the journal Physiological and Biochemical Zoology, shows that the skin of the mangrove killifish picks up the slack for the gills.

Through a series of laboratory experiments, Wright and her team found special cells called ionocytes clustered on the skin of the fish. Ionocytes, normally found on the gills of other fish, are the cells responsible for maintaining the right balance of water and salt in a fish's cells.

"We found the mangrove killifish have roughly as many ionocytes on their skin as on their gills," Wright said. Other fish species have skin ionocytes in larval stages of development, but usually these cells disappear in the skin as the fish develops.

To show that these skin ionocytes were doing the job, the researchers took some mangrove killifish out of water for a period of 9 days. During that time, the fish were left on a surface moist with water containing a radioactive isotope. The researchers found that the isotope eventually turned up in the fish's body.

"It's very clear they're exchanging ions through the skin," Wright said.

The skin of the mangrove killifish is also equipped to help the fish deal with varying salinity, the research found. When out-of-water fish were placed on a surface moist with salt water, the skin ionocytes got bigger, indicating that they're working overtime to keep the right salt balance. When those fish were placed back in water, the skin ionocytes returned to normal size.

It's adaptations like this, Wright says, that make this fish special—even among amphibious fish. Lungfish, for example, need to alter their physiological state to live out of water. But with its special skin, mangrove killifish can maintain all of their normal physiological processes at nearly the same level as being in water—and they can do it for over 60 days.

"They really are very interesting little animals," Wright said.

Danielle M. LeBlanc, Chris M. Wood, Douglas S. Fudge, and Patricia A. Wright, "A Fish Out of Water: Gill and Skin Remodeling Promotes Osmo- and Ionoregulation in the Mangrove Killifish Kryptolebias marmoratus." Physiological and Biochemical Zoology 83:6. An abstract is available here: http://www.journals.uchicago.edu/doi/abs/10.1086/656307.

Physiological and Biochemical Zoology has presented current research in environmental, adaptational, and comparative physiology and biochemistry since 1928. The journal publishes the results of original investigations in animal physiology and biochemistry at all levels of organization, from the molecular to the organismic, focusing on adaptations to the environment. Physiological and Biochemical Zoology is coedited by Drs. Kathleen M. Gilmour and Patricia M. Schulte.

Kevin Stacey | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Studies and Analyses:

nachricht How to design city streets more fairly
18.05.2020 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH

nachricht Insects: Largest study to date confirms declines on land, but finds recoveries in freshwater – Highly variable trends
24.04.2020 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

Im Focus: NASA's Curiosity rover finds clues to chilly ancient Mars buried in rocks

By studying the chemical elements on Mars today -- including carbon and oxygen -- scientists can work backwards to piece together the history of a planet that once had the conditions necessary to support life.

Weaving this story, element by element, from roughly 140 million miles (225 million kilometers) away is a painstaking process. But scientists aren't the type...

Im Focus: Making quantum 'waves' in ultrathin materials

Study co-led by Berkeley Lab reveals how wavelike plasmons could power up a new class of sensing and photochemical technologies at the nanoscale

Wavelike, collective oscillations of electrons known as "plasmons" are very important for determining the optical and electronic properties of metals.

Im Focus: When proteins work together, but travel alone

Proteins, the microscopic “workhorses” that perform all the functions essential to life, are team players: in order to do their job, they often need to assemble into precise structures called protein complexes. These complexes, however, can be dynamic and short-lived, with proteins coming together but disbanding soon after.

In a new paper published in PNAS, researchers from the Max Planck Institute for Dynamics and Self-Organization, the University of Oxford, and Sorbonne...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

New gravitational-wave model can bring neutron stars into even sharper focus

22.05.2020 | Physics and Astronomy

A replaceable, more efficient filter for N95 masks

22.05.2020 | Materials Sciences

Capturing the coordinated dance between electrons and nuclei in a light-excited molecule

22.05.2020 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>