Californian researchers investigating the genetic history of Osedax worms have found that up to twelve further distinct evolutionary lineages exist beyond the five species already described. The new findings about these beautiful sea creatures with unusual sexual and digestive habits are published today in the online open access journal BMC Biology.
Geneticists placed the new Osedax genus in the polychaete annelid family Siboglinidae when it was first discovered on whalebones in Monterey Bay, California in 2004. Siboglinidae or 'beard worms' are among the few known animals that, as adults, completely lack a mouth, gut and anus, and rely entirely on endosymbiotic bacteria for their nutrition. Found to date in the eastern and western Pacific and the north Atlantic, Osedax are unique because they penetrate and digest bones using bacteria housed in a complex branching "root" system. Sexual inequality is also part of daily life for Osedax: harems of dwarf males live inside the tubes of the much larger female.
Robert Vrijenhoek and Shannon Johnson from Monterey Bay Aquarium Research Institute, together with Greg Rouse from Scripps Institution of Oceanography, both in California, US looked at two mitochondrial genes and three nuclear genes from Monterey Bay Osedax worms. Their study revealed 17 distinct evolutionary lineages, clustered into five clades (groups including a single common ancestor and all its descendants). The researchers could tell these clades apart based on the anatomy of the worms as well as their genetics.
Precisely when these Osedax boneworms split from their other beard worm relatives depends whether researchers pick a 'molecular clock' calibrated for shallow or deep-sea invertebrates (Osedax have been found at depths ranging from 30 to 3000 metres). Based on the shallow invertebrate scenario Osedax probably branched off about 45 million years ago when archeocete cetaceans first appeared and then diversified during the late Oligocene and early Miocene when toothed and baleen whales arrived. Using the slower, deep-sea invertebrate clock model Osedax evolved during the Cretaceous and began to diversify during the Early Paleocene, at least 20 million years before the origin of large marine mammals.
Research to settle the evolutionary age of Osedax might examine fossil bones from Cretaceous marine reptiles and late Oligocene cetaceans to find possible trace fossils left by Osedax roots, suggest the authors. "Regardless, the present molecular evidence suggests that the undescribed Osedax lineages comprise evolutionarily significant units that have been separate from one another for many millions of years, and provide a solid foundation for their future descriptions as new species," concludes Vrijenhoek.
Notes to Editors:
3. BioMed Central (http://www.biomedcentral.com/) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.
Graeme Baldwin | EurekAlert!
The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences
Transforming plant cells from generalists to specialists
07.12.2016 | Duke University
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine