New tardigrade found in Japanese car park
Collection of the world’s favourite extremophile animals grows by one. Andrew Masterson reports.
Poking about under a small rock picked up in a Japanese car park – not the most glamorous of activities – has paid a dividend for scientists who discovered a brand new species of tardigrade.
Tardigrades are a very well-known group of tiny animals – micrometazoans, in the jargon – famous for being pretty much indestructible.
The animals, colloquially known as water-bears or moss piglets, are typically no larger than half a millimetre long and boast eight legs. They have been found to be extremely resilient, surviving conditions that would be fatal to pretty much every other living thing, such as extreme temperatures, extreme pressures, dehydration, starvation and radiation.
At the end of the world it will be the tardigrades, not the cockroaches, that will survive.
Members of the tardigrade phylum have been found in living in the deep ocean and in mud volcanoes. Most, however, hang about in moss.
For this reason, a small group of tardigrade researchers led by Daniel Stec of the Jagiellonian University in Poland, recently decided to have a close look at a moss-covered bit of concrete found lying in a car park in the Otsuka-machi district of Tsuruoka City in Japan.
They took the lump back to a laboratory and discovered that it was home to 10 individual tardigrades. These were placed into separate habitats and cultured, producing small populations that could then be analysed and classified using phase contrast light microscopy (PCM), scanning electron microscopy (SEM) and DNA sequencing.
One of these turned out to be a completely new species, a determination made on the basis of the anatomy of the adults and filaments found attached to its eggs.
Stec and colleagues named the species Macrobiotus shonaicus, and formally describe it in a paper in the journal PLOS One. The discovery brings the total number of tardigrade species so far discovered in Japan to 168.
The animals were first identified by zoologist Johann August Ephrain Goeze in 1773. Since then about 1200 species have been found around the globe with the number rising by about 20 each year.