The Velebit mountains of Croatia have several deep caves with some of the world's largest subterranean vertical drops.
Velebit 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 northwest near Senj with the Vratnik mountain pass and ends 145 km to the southeast near the source of the Zrmanja river northwest of Knin.
The Northern Velebit National Park is a national park in Croatia that covers 109 km2 of the northern section of the Velebit mountains, the largest mountain range in Croatia. Because of the abundant variety of this part of the Velebit range, the area was upgraded from a nature reserve in 1999, and opened as a national park in September the same year.
The Clitellata are a class of annelid worms, characterized by having a clitellum - the 'collar' that forms a reproductive cocoon during part of their life cycles. The clitellates comprise around 8,000 species. Unlike the class of Polychaeta, they do not have parapodia and their heads are less developed.
Erpobdella obscura is a freshwater ribbon leech common in North America. It is a relatively large leech and is commonly used as bait by anglers for walleye and other sport fish. In Minnesota, live bait dealers annually harvest over 45,000 kg of bait-leeches, raising concerns of over-harvest.
Zospeum is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Ellobiidae, the salt marsh snails.
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 bodies that can lengthen and contract. Both groups are hermaphrodites and have a clitellum, but leeches typically differ from the oligochaetes in having suckers at both ends and in having ring markings that do not correspond with their internal segmentation. The body is muscular and relatively solid, and the coelom, the spacious body cavity found in other annelids, is reduced to small channels.
Motobdella montezuma is a species of leech which is only found in Montezuma Well, central Arizona, United States. It is a nocturnal pelagic predator that feeds almost exclusively on the endemic amphipod Hyalella montezuma, which it detects using passive sonar and swallows whole.
Erpobdella is a genus of leeches in the family Erpobdellidae. Members of the genus have three or four pairs of eyes, but never have true jaws, and are typically 20–50 millimetres (0.8–2.0 in) long. All members do not feed on blood, but instead are predators of small aquatic invertebrates, which they often swallow whole.
Turtle leeches are a genus, Ozobranchus, of leeches (Hirudinea) that feed exclusively on the blood of turtles. Only two species – Ozobranchus margoi and Ozobranchus branchiatus – are found in the Atlantic coast of the United States and the Gulf of Mexico. Little is known about these leeches due to difficulties in studying their sea turtle hosts.
Haemopis sanguisuga is a species of freshwater leech in the family Haemopidae. It is commonly called the horse-leech, but that is due to the similarity of its appearance to the leech Limnatis nilotica, which sometimes enters the nasal cavities of livestock. Haemopis sanguisuga does not behave in this way. Another synonym for this leech is Aulastomum gulo.
Branchiobdellida is an order of freshwater leech-like clitellates that are obligate ectosymbionts or ectoparasites, mostly of astacoidean crayfish. They are found in the Northern Hemisphere and have a holarctic distribution in East Asia, the Euro-Mediterranean region and North and Central America, with the greatest species diversity being in North and Central America.
Zospeum tholussum or the domed land snail, is a cave-dwelling species of air-breathing land snails in the family Ellobiidae. It is a very small species, with a shell height of less than 2 mm (0.08 in) and a shell width of around 1 mm (0.04 in). Z. tholussum individuals are completely blind and possess translucent shells with five to six whorls. The second whorl of their shells has a characteristic dome-like shape. They are also extremely slow-moving and may depend on passive transportation through running water or larger animals for dispersal.
Erpobdellidae is a family of leeches. It is one of the four families belonging to the suborder Erpobdelliformes of the proboscisless leeches order, Arhynchobdellida.
Erpobdella octoculata is a freshwater leech in the Erpobdellidae family. This species can be found in Europe, the Mediterranean, and the Middle East.
Erpobdella punctata is a leech in the family Erpobdellidae. It is found in freshwater streams and ponds in many parts of North America.
Acanthobdella peledina is a species of leech-like clitellate in the order Acanthobdellida. It feeds on the skin and blood of freshwater fishes in the boreal regions of northern Europe, Asia and North America.
Ozobranchus branchiatus is a species of leech in the family Ozobranchidae. It is found in the Atlantic Ocean and is a permanent parasite of sea turtles, mostly the green sea turtle.
Limnatis nilotica is a species of leech in the family Hirudinidae. It is hematophagous, living on the mucous membranes of mammals.
Zospeum bucculentum is a cave-dwelling species of air-breathing land snails.
