Australian Biological Resources Study

Australian Faunal Directory




Regional Maps

Subclass HIRUDINEA Lamarck, 1818


Compiler and date details

28 April 2002 - Fredric R. Govedich, School of Biological Sciences, Monash University, Melbourne, Victoria, Australia


The Hirudinea, commonly known as leeches, is a group of freshwater and terrestrial annelids closely related to the Oligochaetes. All Hirudinea, a subclass of the Clitellata, have a fixed number of body segments (somites or metameres) including two preoral non-metameric segments (peristome and protostome). The Euhirudinea, the true leeches, have 32 postoral metameric segments (somites) and the Acanthobdellida have 29 postoral metameric segments. In addition, members of the Hirudinea have a posterior sucker for attachment and locomotion and an anterior sucker (Euhirudinea and Acanthobdella livanowi) or chaetae in the first four anterior segments (Acanthobdellida). All Hirudinea have a reduced coelomic system without complete septa in the adults, except in the anterior regions of acanthobdellids and in some glossiphoniids (Euhirudinea).

The true leeches (Euhirudinea) occur worldwide in a wide range of ecosystems including marine, estuarine, moist terrestrial and freshwater systems. They are common in both lentic (ponds and lakes) and lotic (stream and river) ecosystems where they form an integral component of the benthic and occasionally pelagic communities. In a very few cases, predacious species are pelagic predators, e.g. members of the genus Motobdella, but most are sit-and-wait predators feeding on a variety of invertebrates such as chironomids, oligochaetes, amphipods and molluscs. However, some glossiphoniid and erpobdellid species, particularly the genus Motobdella, actively seek prey using chemo- or mechano-reception (Mann 1962; Sawyer 1986a; Sawyer 1986b; Blinn et al. 1987; Blinn et al. 1988; Blinn et al. 1990; Blinn & Davies 1989a; Blinn & Davies 1990; Davies & Everett 1975; Davies et al. 1981; Davies et al. 1982b; Davies et al. 1988; Davies & Kasserra 1989; Davies 1991; Simon & Barnes 1996; Davies & Govedich 2001).

Other leeches, such as some glossiphoniid, piscicolid, hirudinid and haemadipsid species, are temporary ectoparasites feeding on the blood (sanguivory) of vertebrates such as fish, reptiles (turtles and crocodiles), amphibians, waterfowl and mammals. Most sanguivorous species are not host specific and will feed on a number of vertebrate species ranging from amphibians to mammals. In addition, both predacious and sanguivorous leeches are a component of the diet of predacious invertebrates and vertebrates (Cywinska & Davies 1989; Dahl 1998; Greenberg & Dahl 1998). Predacious leeches can often be used to study food-web dynamics, particularly predator-prey interactions, as both predators and prey (Sawyer 1970a; Allen & Allen 1981; Bronmark & Malmqvist 1986; Blinn et al. 1987; Blinn et al. 1988; Blinn et al. 1990; Brown & Strouse 1988; Young 1988; Young & Spelling 1989; Davies & Kasserra 1989; Moser & Willis 1994; Toman & Dall 1997; Dahl 1998).

Predacious leeches are often cryptically coloured and are typically found attached to stones, aquatic vegetation or other submerged substrates. This makes them difficult to collect and results in collections that often underestimate their densities and diversity. Many collection methods, such as dip nets, kick nets, are also potentially biased toward collecting the larger and less cryptic predacious (erpobdellid) and sanguivorous species rather than the more sedentary glossiphoniids. Sanguivorous leeches, in contrast, are often well represented in collections and are more easily identified by many researchers. Due to the lack of widely available and comprehensive keys, especially outside of North America and parts of Europe, many specimens are often lumped together as "leeches" with no distinction made between predacious or sanguivorous forms (Govedich & Davies 1998; Govedich 2001).

Sanguivorous leeches have been recognised for their medicinal properties for many centuries. They have been used as a component of traditional medicines and have recently made a comeback with leeches being used to treat a variety of circulatory diseases and for reconstructive plastic surgery (Sawyer 1986a, 1986b; Mortenson et al. 1998; Oumeish 1998; Zefirova & Maltseva 1998; Lozano et al. 1999; Mamatova et al. 1999; Ulvik 1999).

In addition, salivary extracts such as hyaluronidase (spreading factor), hirudin, hementin, hemenerin and destabilase (anticoagulants) have been extracted and synthesised for medicinal purposes (Sawyer 1986a, 1986b; Blackshear & Ebener 1994; Huang et al. 1998; Arocha-Pinango et al. 1999; Hirsh & Weitz 1999).


I would like to acknowledge Drs Bonnie A. Bain, Ronald W. Davies, P. Sam Lake and Martin Burd for their support and advice. Compilation of this work was assisted by funds from the Australian Biological Resources Study.

Limital Area

Distribution data in the Directory is by political and geographic region descriptors and serves as a guide to the distribution of a taxon. For details of a taxon's distribution, the reader should consult the cited references (if any) at genus and species levels.

Australia is defined as including Lord Howe Is., Norfolk Is., Cocos (Keeling) Ils, Christmas Is., Ashmore and Cartier Ils, Macquarie Is., Australian Antarctic Territory, Heard and McDonald Ils, and the waters associated with these land areas of Australian political responsibility. Political areas include the adjacent waters.

Terrestrial geographical terms are based on the drainage systems of continental Australia, while marine terms are self explanatory except as follows: the boundary between the coastal and oceanic zones is the 200 m contour; the Arafura Sea extends from Cape York to 124 DEG E; and the boundary between the Tasman and Coral Seas is considered to be the latitude of Fraser Island, also regarded as the southern terminus of the Great Barrier Reef.

Distribution records, if any, outside of these areas are listed as extralimital. The distribution descriptors for each species are collated to genus level. Users are advised that extralimital distribution for some taxa may not be complete.



Fixed number of body segments (somites or metameres) including two preoral non-metameric segments (peristome and protostome). Posterior sucker for attachment and locomotion. Reduced coelomic system without complete septa in the adults (except in the anterior regions of acanthobdellids and in some glossiphoniids).


History of changes

Note that this list may be incomplete for dates prior to September 2013.
Published As part of group Action Date Action Type Compiler(s)
12-Feb-2010 (import)