A special group of millipedes is capable of coiling themselves into a perfect ball when disturbed, like a hedgehog or an armadillo, and are therefore called 'pill millipedes' or Sphaerotheriida (Latin for 'Ball Animals'). This mechanism helps them to defend themselves against potential predators, but makes mating attempts problematic.
Zoosphaerium solitarium Wesener, 2009, a giant pill-millipede species discovered in 2009 on Madagascar. This species is only known from a single hill in northern Madagascar that is endangered by ongoing forest destruction.
Photo by Jörn Köhler, 2008
Zoosphaerium solitarium Wesener, 2009, Giant pill-millipedes can roll into a perfect ball, their only defence mechanism. Unlike other millipedes, giant pill-millipedes cannot excrete poisonous defence fluids. The rolling-in behaviour is a good defence against predators, but leads to communication break-down with a potential mate.
Photo by Jörn Köhler
Since the animals coil into a perfect ball when touched, it becomes impossible for the male to induce the female to open-up again, if it does not give a special signal. Therefore, males of some species rub special ribs on the last pair of legs across nubs on their body shield to produce sounds, similar to cicada songs, which they then broadcast to the female. This way, the female can detect that the disturbance came from a suitable partner of the same species and can, if willing, decide to unroll so that the mating can begin.
These complex mating mechanisms were described in the journal Naturwissenschaften by a team of researchers from Germany (Bonn, Darmstadt and Frankfurt) and Belgium (Tervuren). The scientists could clarify the mechanism of sound production, as well as demonstrate that each giant pill-millipede species produces a different sound. Mix-ups between species are therefore impossible. Astonishingly, giant pill-millipedes are not even capable of hearing. The signal which induces the females to open-up is the species-specific vibration pattern alone – 'good vibrations' in the literal sense!
Almost as interesting as the vibrating millipedes is the history of its discovery. In 1972 Dr. Haacker, a 33-year old Zoologist, travelled with his student Stefan Fuchs to South Africa to take recordings and study the mating of giant pill-millipedes. They collected a striking number of animals and numerous recordings of their sounds. Unfortunately, Dr. Haacker died of a rare form of leukaemia only a few weeks after he returned to Germany, and his material was left unstudied. His student packed all the animal samples, recordings, and lab book into a large box which he carried with him during his whole life as a researcher, storing it in several cellars and attics, always wondering if he should get rid of the box.
More than 30 years after his South African expedition with Dr. Haacker, Stefan Fuchs stumbled upon the work of the then-student Thomas Wesener, who published an article on newly discovered species of giant pill-millipedes from Madagascar. Fuchs wrote a note to Wesener, who is now a curator at the Museum Koenig in Bonn, Germany, describing the work he had done in South Africa and the box filled with history. Intrigued by the note, Wesener met with Fuchs to examine the contents of the box. Inside the box they found a hand-written field diary and Dr. Haacker’s lab book, as well as 80 baby food jars filled with conserved millipedes. It was a welcome surprise that most animals were still well-conserved after 30 years of storage; even the labels were still readable, but disintegrated when touched.
Even with the renewed interest in the project, it took a while longer until scientific work on the material became possible. The specimens of the Haacker-collection could not be determined until 2002, when Didier van den Spiegel from the Africa Museum in Tervuren, Belgium and several colleagues published a taxonomic revision of the giant pill-millipedes from South Africa. The analysis of the old sound files, whose quality was mixed, made the introduction of Jörn Köhler from the Hessenian State Museum Darmstadt necessary, who had some experience in the analysis of frog calls.
This long history of the research to understand the function of the sounds produced by millipedes is a good example of how important the precise documentation of scientific data is for future generations, and that many scientific riddles can only be solved through cooperation.
Wesener, T., J. Köhler, S. Fuchs & D. van den Spiegel (2011): How to uncoil your partner - "mating songs" in giant pill-millipedes (Diplopoda: Sphaerotheriida). Naturwissenschaften 98 (11): 967–975.
Black&White low quality video from 1972, showing mating attempts of giant pill-millipedes
Sound files of different giant pill-millipede species
www.zfmk.de/_downloads/ZFMKwesener_S_similare_stridulation.wavContact: Dr. Thomas Wesener, Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn
Sabine Heine | idw
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction