Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Unravelling The Ecology Of Snail Shell Coiling


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:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>