Newly described amphipod species already under threat
Biologists at Eawag have described a new amphipod species which is endemic to the Alps. While alpine lakes provide relatively undisturbed habitats for Gammarus alpinus, this species is being displaced by an invasive amphipod in Lake Constance.
|Gammarus alpinus preserved in alcohol: the distinctive morphological features of this amphipod species|
are only apparent under the microscope [Credit: Eawag, Roman Alther]
One of the amphipods whose distribution Alther has investigated is Gammarus lacustris – a cosmopolitan species, found in Asia and America as well as Europe.
Wishing to find out how closely alpine gammarid populations are related, Alther collected samples from lakes in France, Italy, Austria and Switzerland.
These were complemented with specimens from the collections of a number of natural history museums, together with published genetic data. In the laboratory, the individual gene sequences were compared and, with the aid of a computer, a phylogenetic tree was constructed.
Alther explains: “To our surprise, we found that the alpine populations form a completely separate branch, differing from the non-alpine populations of Gammarus lacustris. This clear genetic differentiation provides strong evidence that the alpine gammarids represent a distinct species.”
Source: EAWAG: Swiss Federal Institute of Aquatic Science and Technology [September 08, 2016]