Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Peanut worms are annelids

03.03.2011
The phylum Annelida has just gained a new member / Peanut worm is no longer recognized as separate group

Recent molecular phylogenetic analysis has shown that the marine animals known as peanut worms are not a separate phylum, but are definitely part of the family of annelids, also known as segmented worms. This is a classification that seemed questionable in the past in view of the fact that peanut worms – or the Sipunculidae, to give them their scientific name – have neither segments nor bristles.


Sipunculus nudus of the group of Sipunculidae with a length of about 8 centimeters. photo/©: Dr Anja Schulze, Texas A&M University at Galveston, USA

The latter are considered typical characteristics of annelids, which include more than 16,500 identified species and to which our common earthworm belongs. "Our molecular data clearly demonstrates that there is no doubt anymore that the Sipunculidae should be classified as members of these segmented worms," explains Dr Bernhard Lieb of the Institute of Zoology at Johannes Gutenberg University Mainz (JGU). The results were obtained as part of a broad study in which the phylogenetic development and relationships within the phylum Annelida were analyzed in terms of basic molecular biology to be then re-evaluated. Participating in the project are the universities of Osnabrück, Potsdam, Mainz, and Leipzig, together with the Max Planck Institute of Molecular Genetics in Berlin. The results have now been published online in the journal Nature.

"The relationships between the various annelids with regard to both morphological and molecular biological aspects have been a matter of dispute," states Lieb. Segmented worms are the most prevalent of marine macrofauna – their habitat ranges from tidal zones to the deep oceans. Usually, they have been divided into two main classes: the Clitellata, which have few bristles, e.g. earthworms, and leeches on the one hand and the Polychaeta, literally the 'many bristled', on the other hand. The evolutionary and deep branching patterns of annelid lineage are still the subject of on-going scientific debate, although it has become increasingly clear that other groups that had previously been classified separately, such as peanut worms and beard worms, are actually members of this phylum. By means of identifying some 48,000 amino acid positions in 34 different representatives of the phylum Annelida, the research group headed by the universities of Osnabrück and Potsdam has put together the hitherto most detailed database for the family of segmented worms. This has enabled the group to re-evaluate and reconstruct the phylogenetic interrelationships and evolution of this extensive and highly diverse group of animals.

The molecular data on Sipunculus nudus – the peanut worm – gathered by the team in Mainz led by Bernhard Lieb shows that the genetic characteristics of the worm, which lives in sand and silt at the bottom of the sea, clearly indicates that it is a member of the annelid family. In evolutionary terms the peanut worm is likely to be a basal group that diverged very early during evolution. It is conjectured on the basis of the sparse fossil record that the annelids first appeared in the Cambrian Period, roughly 550-490 million years ago. "We assume that segmentation was a very early characteristic of the annelids and that the peanut worm has lost its segmentation during the course of evolution," clarifies Lieb.

Primarily, new DNA sequencing technologies, so-called next-generation sequencing (NGS), made such comprehensive genetic investigations become possible. The Illumina Hiseq2000 sequencer recently acquired by the Institute of Genetics at JGU can analyze vast amounts of data, and sequence up to 200 gigabases of DNA per run within a single week. This means that whole genomes can be sequenced in a relatively short time, opening up completely new avenues for wide-ranging research.

Petra Giegerich | idw
Further information:
http://www.uni-mainz.de/eng/14040.php
http://www.staff.uni-mainz.de/lieb/

Further reports about: Annelida DNA Genetics Peanut Sipunculidae deep ocean molecular data segmented worms

More articles from Life Sciences:

nachricht Complementing conventional antibiotics
24.05.2018 | Goethe-Universität Frankfurt am Main

nachricht Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

When corals eat plastics

24.05.2018 | Ecology, The Environment and Conservation

Surgery involving ultrasound energy found to treat high blood pressure

24.05.2018 | Medical Engineering

First chip-scale broadband optical system that can sense molecules in the mid-IR

24.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>