Featured Research

from universities, journals, and other organizations

Scientists discover reasons behind snakes' 'shrinking heads'

Date:
March 19, 2013
Source:
University of Adelaide
Summary:
Scientists have uncovered how some sea snakes have developed 'shrunken heads' -- or smaller physical features than their related species.

A small-headed sea snake foraging in waters off the Ryuku Islands.
Credit: Photo by Yoshitaka Tahara

An international team of scientists led by Dr Kate Sanders from the University of Adelaide, and including Dr Mike Lee from the South Australian Museum, has uncovered how some sea snakes have developed 'shrunken heads' -- or smaller physical features than their related species.

Their research is published today in the journal Molecular Ecology.

A large head -- "all the better to eat you with" -- would seem to be indispensable to sea snakes, which typically have to swallow large spiny fish. However, there are some circumstances where it wouldn't be very useful: sea snakes that feed by probing their front ends into narrow, sand eel burrows have evolved comically small heads.

The team has shown normal-shaped sea snakes can evolve such "shrunken heads" very rapidly. This process can lead to speciation (one species splitting into two).

The small-headed populations are also much smaller in absolute size than their ancestors, and these shape and size differences mean they tend to avoid interbreeding with their large-headed ancestors.

Dr Lee says, "A team led by my colleague Dr Kate Sanders (University of Adelaide) has been investigating genetic differences across all sea snakes, and we noticed that the blue-banded sea snake (Hydrophis cyanocinctus) and the slender-necked sea snake (Hydrophis melanocephalus) were almost indistinguishable genetically, despite being drastically different in size and shape.

"The slender-necked sea snake is half the size, and has a much smaller head, than the blue-banded sea snake.

"This suggested they separated very recently from a common ancestral species and had rapidly evolved their different appearances.

"One way this could have happened is if the ancestral species was large-headed, and a population rapidly evolved small heads to probe eel burrows -- and subsequently stopped interbreeding with the large-headed forms."

Dr Sanders says the research could have wider implications in other scientific studies: "Our results highlight the viviparous sea snakes as a promising system for studies of speciation and adaptive radiation in marine environments."


Story Source:

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


Journal Reference:

  1. Kate L. Sanders, Arne R. Rasmussen, Mumpuni, Johan Elmberg, Anslem de Silva, Michael L. Guinea, Michael S. Y. Lee. Recent rapid speciation and ecomorph divergence in Indo-Australian sea snakes. Molecular Ecology, 2013; DOI: 10.1111/mec.12291

Cite This Page:

University of Adelaide. "Scientists discover reasons behind snakes' 'shrinking heads'." ScienceDaily. ScienceDaily, 19 March 2013. <www.sciencedaily.com/releases/2013/03/130319160435.htm>.
University of Adelaide. (2013, March 19). Scientists discover reasons behind snakes' 'shrinking heads'. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2013/03/130319160435.htm
University of Adelaide. "Scientists discover reasons behind snakes' 'shrinking heads'." ScienceDaily. www.sciencedaily.com/releases/2013/03/130319160435.htm (accessed July 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Dogs Appear To Become Jealous Of Owners' Attention

Dogs Appear To Become Jealous Of Owners' Attention

Newsy (July 23, 2014) A U.C. San Diego researcher says jealousy isn't just a human trait, and dogs aren't the best at sharing the attention of humans with other dogs. Video provided by Newsy
Powered by NewsLook.com
Professor Creates Site Revealing Where People's Cats Live

Professor Creates Site Revealing Where People's Cats Live

Newsy (July 23, 2014) ​It's called I Know Where Your Cat Lives, and you can keep hitting the "Random Cat" button to find more real cats all over the world. 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:
from the past week

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