Deep-sea algae may be 'living fossils'

Nov 19, 2010 by Lin Edwards report

(PhysOrg.com) -- Researchers in the US and Belgium say two types of deep-sea seaweed may be representatives of ancient forms of algae previously unrecognized.

The two seaweed species grow at depths of around 210 meters below the surface, which is extremely deep for photosynthetic organisms and may mean they could be "living fossils" of the earliest known green plants.

The seaweeds, from the genera Verdigellas and Palmophyllum, are also found in shallower water but generally under overhanging ledges where there is less light. Samples of Verdigellas umbracola were taken from the western Atlantic Ocean, while the Palmophyllum samples were taken from waters around New Zealand.

Leader of the research team, Professor Frederick Zechman of California State University, said the seaweeds, which had already been identified, seem to have special chlorophyll pigments that enable them to use low intensity blue light and live in deeper waters than most . Zechman said the algae were also unusual in that they are multicellular but there appears to be no meaningful interaction between individual cells, which form part of a gelatinous matrix that takes on shapes such as stalks.

In the paper, published in the Journal of Phycology, Zechman and the team from across the US and Belgium described their of the DNA in the nuclei and chloroplasts within the algae cells. The genetics revealed the species have much older origins than previously suspected.

The scientists expected the algae to be members of the Chlorophyta, the group (known scientifically as a clade) to which all other except those with the most complex structures belong. The other clade includes the and the most complex green algae (charophytes or stoneworts). The Verdigellas and Palmophyllum algae belonged to neither clade, but instead appeared to be members of an extremely ancient group of green plants.

Zechman said the algae should be assigned to their own Order, the Palmophyllales, because they are so different from other algae. He added that a comparison of the gene sequences of the algae to the same genes in other plants revealed that the are among the earliest, if not the earliest, diverging green plants, originating before about a billion years ago when the two groups of plants diverged.

Zechman said the findings could change “vastly” the scientific view of the ancestor to all the green plants in the world today, which is at present assumed to be a single-celled aquatic plant able to move around with the help of a flagellum (tail). The key to the amazing longevity of the Verdigellas and Palmophyllum may be the depth at which they live, since in deep water there is less variation in temperature, less stress from wave action, and fewer grazing herbivores.

Explore further: Researchers identify new mechanism to aid cells under stress

More information: An Unrecognized Ancient Lineage of Green Plants Persists in Deep Marine Waters, Journal of Phycology, DOI:10.1111/j.1529-8817.2010.00900.x

Frederick W Zechman: fresca.calstate.edu/faculty/2038

Related Stories

Green energy from algae

Jun 25, 2010

(PhysOrg.com) -- Visitors to this year’s UK Royal Society Summer Exhibition will have a chance to discover how scientists from the University of Cambridge are studying ways to harness algae as a renewable ...

Noxious algae gone, but who knows how long

Jan 03, 2007

Recent storms may have washed away algae blooms in a Florida chain of lakes, but experts said algae threats remain because of pollution feeding the lakes.

Green sea slug makes chlorophyll like a plant

Jan 12, 2010

(PhysOrg.com) -- Scientists from the University of South Florida in Tampa have found a green sea slug is able to synthesize chlorophyll like a plant, which makes it the first animal known to be capable of ...

Recommended for you

Researchers identify new mechanism to aid cells under stress

5 hours ago

A team of biologists from NYU and Harvard has identified new details in a cellular mechanism that serves as a defense against stress. The findings potentially offer insights into tumor progression and neurodegenerative diseases, ...

Researchers image and measure tubulin transport in cilia

6 hours ago

Defective cilia can lead to a host of diseases and conditions in the human body—from rare, inherited bone malformations to blindness, male infertility, kidney disease and obesity. Scientists knew that somehow ...

Researchers find unusually elastic protein

8 hours ago

Scientists at Heidelberg University have discovered an unusually elastic protein in one of the most ancient groups of animals, the over 600-million-year-old cnidarians. The protein is a part of the "weapons system" that the ...

How malaria-spreading mosquitoes can tell you're home

Jan 22, 2015

Females of the malaria-spreading mosquito tend to obtain their blood meals within human dwellings. Indeed, this mosquito, Anopheles gambiae, spends much of its adult life indoors where it is constantly expose ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.