Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unravelling The Ecology Of Snail Shell Coiling

01.09.2003


Ecologists are taking to the trees in a bid to unravel the ecology of shell coiling in snails. Speaking at the British Ecological Society’s Annual Meeting, being held at Manchester Metropolitan University on 9-11 September 2003, Dr Paul Craze of the University of Plymouth will explain how examining the proportion of right- and left-coiling individuals in a species of Bornean tree snail could help ecologists understand how new species arise.



The vast majority of snail species are almost exclusively dextral, or right-coilers, with just the occasional sinistral, or left-coiling, individual. However, in a small number of snail species there appears to be a stable balance between the number of right- and left-coilers. Coil direction in snails is inherited from the mother and is controlled by a single genetic locus or region, and coil direction is important because it is difficult for right-coiling snails to mate with left-coiling snails.

The fact that left- and right-coiling snails cannot align themselves properly during mating is, however, more than an irritation to the snails and an interesting puzzle for ecologists. Understanding how new species arise is a fundamental biological problem, and in the case of snails, some ecologists believe that the existence of left- and right-coiling individuals could be one mechanism for sympatric speciation (the development of new species by isolating them other than geographically). Since left-coiling and right-coiling snails find it hard to mate with each other they may, over time, develop into separate species.


Dr Craze and Dr Menno Schilthuizen of the Universiti Malaysia Sabah studied shell coiling in Amphidromus martensii, a snail that lives in the rainforests of Borneo, and one of the few species that is composed of roughly 50% right- and 50% left-coiling individuals, to find out what factors are responsible for maintaining this 50:50 split, and whether or not the right- and left-coilers show evidence of diverging towards becoming different species.

“There has been virtually no ecological study of shell-coiling polymorphism, so the first thing we were interested in was whether the 50:50 ratio that we know exists at the medium scale (ie between sites separated by tens of kilometres) also exists at a smaller scale (ie between sites separated by tens of metres), or whether the right coilers occupied different habitats from the left coilers,” Dr Craze says.

Because A. martensii lives in the forest canopy, Dr Craze chose to collect shells of dead snails from the ground. “We found equal numbers of left and right coilers no matter what scale we chose, which suggests that we are dealing with a truly balanced polymorphism and that these snails are not at the early stages of speciation. If that turns out to be the case, we need to identify what factors are responsible for keeping the polymorphism so balanced,” Dr Craze explains.

However, to make sure that the results they have found are not only confined to snail shells found on the ground, Dr Craze will be repeating the experiment by hanging from a rope in the rainforest looking at live snails in the forest canopy. “We also plan to use small snail-sized radio transmitters to track movements of snails to see how many snails of each coil-type an individual is likely to encounter and so work out the potential for gene flow between areas,” he says.

According to Dr Craze: “Our work may have some interesting implications. Studies of the ecological factors responsible for maintaining balanced polymorphism are still quite rare. On the other hand, if some degree of divergence between the coil-types is discovered, we have a model system for studying what may be an interesting mechanism of sympatric speciation.”

Dr Craze will present his full findings at 15:00 on Tuesday 9 September 2003.

Becky Allen | alfa
Further information:
http://www.britishecologicalsociety.org/

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>