The results of longlasting research of the dinaric cave clam Congeria (Bivalvia: Dreissenidae) published in the international magazine "Frontiers in Zoology".
Two, so far unknown species of clams were discovered in underground waters od the Dinaric Karst, which is also their only habitat. Cave clam which the experts gave scientific name Congeria jalzici was found in the underground waters of river Lika and Kupa catchment areas and the sister species Congeria mulaomerovici in underground waters of the river Sana catchment area in west Bosnia.
Congeria is the object of longlasting research carried out by the members of CBSS through a series of projects financed by the Nature protection State department, Nature protection Directorate of the Ministry of culture and the Environmental protection and energy efficiency Fund. The research began in 2007 and are still in progress today. Besides numerous members of the Croatian Biospeleological Society, many cavers from different caving clubs also contributed in the research such as: Speleological club Samobor, SO HPD Velebit, SD Karlovac and SU Estavela.
New methods in molecular biology enabled these results. Because of the stable and very similar conditions in the underground, the appearance of the clams remained the same, although they evolved in isolation one from another and have genetically separated in new animal species. Using the molecular clock of the clam, the experts were able to read the geological past and get insight on the conditions on the Earth`s surface and on the evolution of the greater group (family Dreissenidae) to which the the genus Congeria belongs to, during the last more than thirty million years.
Clams are the residual of the rich fauna that used to live in the former Paratetis see, which 30 milion years ago spread from Switzerland to the Bajkal lak, and then "fell apart" in large lakes, like the Panonian see, to completely disappear in the end. More then 30 species of genus Congeria were found in fossil material in the area of today's Croatia and Bosnia and Hercegovina. By the middle of the 20th century the experts considered them to be completely extinct, when in Popovo polje the first live specimen of genus Congeria was found in the underground waters in which it entered by the disappearance of the Panonian sea and successfully adapted there. Analysis show that C. jalzici and C. mulaomerovici separated little less then million years ago.
Read the whole article at the following link.
Bilandžija, H., Morton, B., Podnar, M., Ćetković, H. (2013): Evolutionary history of relict Congeria (Bivalvia:Dreissenidae): unearthing the subterranean biodiversity of the Dinaric Karst. Frontiers in Zoology 10:5, p. 17