Featured Research

from universities, journals, and other organizations

Lizards And Salamanders May Use Lungs To Hear, Study Says

Date:
March 7, 2002
Source:
Ohio State University
Summary:
Certain species of salamanders and lizards can actually hear through their lungs, according to a new study at Ohio State University. The research extends previous studies showing that some types of earless frogs and toads use their lungs to pick up sound vibrations, said Thomas Hetherington, an associate professor of Evolution, Ecology and Organismal Biology at Ohio State.

COLUMBUS, Ohio - Certain species of salamanders and lizards can actually hear through their lungs, according to a new study at Ohio State University.

Related Articles


The research extends previous studies showing that some types of earless frogs and toads use their lungs to pick up sound vibrations, said Thomas Hetherington, an associate professor of Evolution, Ecology and Organismal Biology at Ohio State.

The results of the current study suggest lung-based hearing may exist in a variety of land-based animals.

"This primitive system of hearing may have been the auditory system for the first animals that lived on land," Hetherington said. "And it appears that it may still be important for some species today, particularly ones that lack middle ears."

Hetherington examined four species of salamanders and three species of lizards to determine if the lungs might play a role in their hearing. Although salamanders lack middle and external ears, both groups of animals have inner ears that can process sound.

In his studies, Hetherington found that sound causes the animal's chest to vibrate, and the vibrations are carried by air from the lungs to the animal's inner ear where it is processed as sound.

The experiments make clear the importance of the lungs for hearing - one species of salamander that lacked lungs did not show the chest vibrations that the others did. And when the lungs of the other species were filled with oxygenated saline instead of air, the animals' chests no longer showed vibrations.

The study was published in a recent issue of the Journal of Comparative Physiology A: Sensory, Neural and Behavioral Physiology.

Hetherington put the animals on a table in a soundproof chamber. He bounced a beam of laser light off of each animal's skin to measure the skin's movement when exposed to various sound frequencies emitted from a speaker inside the chamber.

Low frequencies caused the greatest vibrations: peak motion ranged from 1,600 to 2,500 hertz in small newts (newts are a type of salamander); from 1,250 to 1,600 Hz in larger salamanders; and from 1,000 to 2,000 Hz in lizards. Lizards have middle ears, which is where the eardrum is located, and the skin covering this area of the animal's head vibrated at slightly higher frequencies of about 2,000 to 3,000 Hz. The lungless salamanders didn't respond at any frequency.

To determine how dependent the animals were on their lungs for hearing, Hetherington filled the lungs of three red-spotted newts and three green anoles (an anole is a tropical lizard that can change color) with oxygenated saline solution - the oxygen in the solution allowed the animals to keep breathing. Sure enough, the response to sound - the vibrations - dropped.

"It practically disappeared," he said. "While sound may get in through other routes, the lungs are clearly the most sensitive to sound waves," Hetherington said.

After filling the lungs with the saline solution, the vibrations noticeably decreased by about 90 percent in all of the animals. The animals' sensitivity to sound was restored when the lungs were emptied and filled again with air.

While Hetherington knew from his previous research that certain frog species depended on their lungs to conduct sound, he wasn't sure before these studies that the same process held true in other amphibians and small reptiles, whose lungs are covered with ribs and muscle.

"Using the lungs to detect sound seems to be especially useful for small animals with really small lungs," Hetherington said. "Thinner body walls respond more readily to sound, so it may be that the lungs can capture a wide range of frequencies only in small animals."


Story Source:

The above story is based on materials provided by Ohio State University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio State University. "Lizards And Salamanders May Use Lungs To Hear, Study Says." ScienceDaily. ScienceDaily, 7 March 2002. <www.sciencedaily.com/releases/2002/03/020305073309.htm>.
Ohio State University. (2002, March 7). Lizards And Salamanders May Use Lungs To Hear, Study Says. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2002/03/020305073309.htm
Ohio State University. "Lizards And Salamanders May Use Lungs To Hear, Study Says." ScienceDaily. www.sciencedaily.com/releases/2002/03/020305073309.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins