Featured Research

from universities, journals, and other organizations

Corals Defy Species Classification

Date:
February 19, 2003
Source:
Netherlands Organization For Scientific Research
Summary:
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.

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 Curaηao. 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.

###

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


Story Source:

The above story is based on materials provided by Netherlands Organization For Scientific Research. Note: Materials may be edited for content and length.


Cite This Page:

Netherlands Organization For Scientific Research. "Corals Defy Species Classification." ScienceDaily. ScienceDaily, 19 February 2003. <www.sciencedaily.com/releases/2003/02/030219080258.htm>.
Netherlands Organization For Scientific Research. (2003, February 19). Corals Defy Species Classification. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2003/02/030219080258.htm
Netherlands Organization For Scientific Research. "Corals Defy Species Classification." ScienceDaily. www.sciencedaily.com/releases/2003/02/030219080258.htm (accessed April 24, 2014).

Share This



More Plants & Animals News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Monkeys Are Better At Math Than We Thought, Study Shows

Monkeys Are Better At Math Than We Thought, Study Shows

Newsy (Apr. 23, 2014) — A Harvard University study suggests monkeys can use symbols to perform basic math calculations. Video provided by Newsy
Powered by NewsLook.com
Raw: Leopard Bites Man in India

Raw: Leopard Bites Man in India

AP (Apr. 22, 2014) — A leopard caused panic in the city of Chandrapur on Monday when it sprung from the roof of a house and charged at rescue workers. (April 22) Video provided by AP
Powered by NewsLook.com
Iowa College Finds Beauty in Bulldogs

Iowa College Finds Beauty in Bulldogs

AP (Apr. 22, 2014) — Drake University hosts 35th annual Beautiful Bulldog Contest. (April 21) Video provided by AP
Powered by NewsLook.com
805-Pound Shark Caught Off The Coast Of Florida

805-Pound Shark Caught Off The Coast Of Florida

Newsy (Apr. 22, 2014) — One Florida fisherman caught a 805-pound shark off the coast of Florida earlier this month. 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