New species of Water Bears have been foundScience 21.04.2015
A new species of water bear (Tardigrada), Echiniscus pardalis n. sp., is described from two moss samples collected in the Parco Naturale delle Alpi Marittime (NW Italy) by Peter Degma & Ralph O. Schill. It belongs to the Echiniscus arctomys species-group, but differs from other 49 known members of the group mainly by the irregularly and distantly scattered deep pores on the plates and by a unique subsurface cuticular pattern on the plates, resembling that of a leopard’s fur. Therfore the the species name refers to the similarity of the subsurface dorsal plates pattern to a leopard’s spots.
Tardigrades (tardus "slow" + gradi to "step"), also well known as "water bears", are microscopic small metazoans. Most of the over 1000 known tardigrade species are cosmopolitan species. The first tardigrades were discovered in 1773 after microscopes were invented. Around 800 terrestrial species live in moist environments that facilitate the animal's gaseous exchange and avoid desiccation. However, such habitats frequently undergo seasonal changes that impact animals, but they are able to survive these periods of adverse conditions due to the ability to enter a cryptobiotic state. A cryptobiotic state could encompass processes induced by desiccation (anhydrobiosis), low temperature (cryobiosis), lack of oxygen (anoxybiosis) or combinations of these. This capability has been dramatically achieved by tardigrades.
In this state, they are capable of surviving for very long periods. Although it has been assumed that tardigrades have a very long life span, little information is available about their exact longevity. In the cryptobiotic stage, tardigrades show extraordinary tolerance to physical extremes including high energy radiation, immersion in organic solvents, brief exposure to high temperatures and prolonged exposure to indefinitely low temperatures. When environmental conditions are adequate, tuns rehydrate and the animals resume metabolic activity. However, the mechanisms are poorly understood.
Degma P. & Schill R. O. 2015. — Echiniscus pardalis n. sp., a new species of Tardigrada (Heterotardigrada, Echiniscidae, arctomys group) from the Parco Naturale delle Alpi Marittime (NW Italy), in Daugeron C., Deharveng L., Isaia M., Villemant C. & Judson M. (eds), Mercantour/Alpi Marittime All Taxa Biodiversity Inventory. Zoosystema 37 (1): 239-249.