''Erpobdella mestrovi'' is a species of

troglobitic A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves. These are separate from species that mainly live in above-ground habitats but are also able to live u ...

leech Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodie ...

found only in deep caves in Northern

Velebit Velebit (; it, Alpi Bebie) is the largest, though not the highest, mountain range in Croatia. The range forms a part of the Dinaric Alps and is located along the Adriatic coast, separating it from Lika in the interior. Velebit begins in the nor ...

, part of the

Dinaric Alps The Dinaric Alps (), also Dinarides, are a mountain range in Southern and Southcentral Europe, separating the continental Balkan Peninsula from the Adriatic Sea. They stretch from Italy in the northwest through Slovenia, Croatia, Bosnia and Herz ...

Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = "Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capit ...

. The leech was first found in

Lukina jama The Velebit mountains of Croatia have several deep caves with some of the world's largest subterranean vertical drops. The "Lukina jama" cave is 1431 m deep (2013), the deepest cave in Croatia, 14th deepest cave in the world and the deepest cave i ...

in 1994, which at 1431 meters deep is the deepest cave in Croatia. The leech has been found in several other caves systems in

such as Slovacka jama (-1320 m), Olimp (-531 m) and Velebita (-1026 m), and is currently considered

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Croatia. This leech inhabits underground streams and has several

adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the po ...

s to deal with a

rheophilic A rheophile is an animal that prefers to live in fast-moving water. Examples of rheophilic animals Insects *Many aquatic insects living in riffles require current to survive. *''Epeorus sylvicola'', a rheophilic mayfly species ( Ephemeroptera) ...

and

lifestyle. The leech lacks eyes, has pale skin, and strong suckers to help it move around its environment. A flat body prevents it from being swept away by the current. The leech moves in a caterpillar-like motion, alternating between its posterior and oral sucker. There are several extremities protruding from the sides that are theorized to be gills. This leech grows about 25 to 40 mm (1 to 1.6 in) in length and can handle temperatures as low as 4 to 6 °C (39.2– 42.8 °F).

References

Leeches Annelid genera Endemic fauna of Croatia {{annelid-stub