Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Corals defy species classification

18.02.2003


Classifying corals in terms of species is a risky business. Biologist Onno Diekmann from the University of Groningen has discovered that four species of stone corals differ so little in terms of their genetic material that they can scarcely be termed separate species.



Corals are formed by a collection of identical coral polyps which together form a coral colony. Onno Diekmann compared the genetic material from six different species of coral from the Madracis genus, which are found in the coral reefs around Curaçao. The coral exists in many different physical forms. There are knobby, branched and crust-forming colonies. The corals grow at depths varying from 2 to 70 metres. The external appearance is partly determined by the environmental conditions, such as temperature, water movements and the amount of available light. Therefore, it is difficult to determine if two coral colonies belong to the same species, if only the external appearance is used.

Two forms of Madracis were found to be clearly distinct species. Yet four other species exhibited a considerable overlap in the genetic variation. Therefore, which of the four species these corals belong to cannot be determined with any certainty. The spectrum of intermediate forms indicates that these four species can interbreed. However, the four species do differ in their physical appearance. In addition to the colony form there are also smaller characteristics where differences might be exhibited. Yet none of the individual microcharacteristics can be used to unequivocally determine which species an individual coral belongs to. For this several characteristics need to be analysed at the same time.


It is difficult to apply the term ’species’ to corals. Perhaps this is because they are found in the ocean where physical barriers to reproduction between different species are not or are scarcely present. The ocean currents determine the direction in which a species can be moved. Due to sea level changes the ocean current patterns are highly variable as a result of which the mixing of various coral ’species’ can continually occur.

For corals where fertilisation and development of the larvae takes place in water, it was already known that differences between species can be sufficiently small to allow interbreeding to take place with the production of fertile offspring. This research on Madracis has demonstrated that corals which reproduce by internal fertilisation and the hatching of offspring can also interbreed.



For further information please contact Onno Diekmann (Department of Marine Biology, University of Groningen), tel +31 (0)50 3632226, fax +31 (0)50 3632261, e-mail: o.e.diekmann@biol.rug.nl. The defence of the doctoral thesis will take place on 27 February 2003. Mr Diekman’s supervisor is Prof. R.P.M. Bak.

Image at www.nwo.nl/nieuws

The research was funded by the Netherlands Organisation for Scientific Research (NWO).


Nalinie Moerlie | EurekAlert!
Further information:
http://www.nwo.nl

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>