__NOTOC__ Haemadipsidae (From Greek "haima" and "dipsa" ("blood" and "thirst", respectively)) are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of jawed leeches. They are a

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

group of hirudiniform proboscisless leeches. These leeches have five pairs of eyes, with the last two separated by two eyeless segments. The family is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

, containing only the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Haemadipsinae. However, the family can apparently be divided into two or three distinct lineages. At least one of the proposed

splits A split (commonly referred to as splits or the splits) is a physical position in which the legs are in line with each other and extended in opposite directions. Splits are commonly performed in various athletic activities, including dance, figu ...

, while not a distinct family, might be a valid subfamily. Haemadipsids have two or three jaws. The two-jawed (duognathous) species were classified in a number of largely monotypic or non-monophyletic genera, so they were placed into a single monophyletic genus called ''

Chtonobdella ''Chtonobdella'' is a genus of land leeches belonging to the family Haemadipsidae, erected by Adolph Grube in 1866.Grube AE (1866) ''Landblutegeln asu Südaustralien. Jahres-Bericht der Schlesischen Gesellschaft für Vaterländische Cultur'' 43 ...

''. To increase grip, their caudal suckers have textured "friction" or "sucker" rays. Commonly known as jawed land leeches, these

annelid The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to vario ...

s are known from

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

and

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

regions around the Indian and

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. Well-known Haemadipsidae are for example the Indian Leech ('' Haemadipsa sylvestris'') and the ''yamabiru'' or Japanese Mountain Leech (''Haemadipsa zeylanica''). Members of the family feed on

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is com ...

, except '' Idiobdella'' which has adapted to eat small

snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...

s. The other notable group of jawed blood-sucking leeches are the

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

Hirudinidae. The

Xerobdellidae Xerobdellidae are a small family of jawed leeches in the order Arhynchobdellida. Xerobdellidae have three jaws and five pairs of eyes, the fourth and fifth being separated by one or two eyeless segments. The genera placed herein occur in Chile ( ...

are sometimes included in the Haemadipsidae, but their status as a distinct family is supported by

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is cal ...

analysis of the

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics * Nuclear space *Nuclear ...

18S and 28S rDNA and

mitochondrial A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used ...

COI

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

s as well as the

anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

of their

sexual organ A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting ...

s and

nephridia The nephridium (: nephridia) is an invertebrate organ, found in pairs and performing a function similar to the vertebrate kidneys (which originated from the chordate nephridia). Nephridia remove metabolic wastes from an animal's body. Nephridia co ...

; the latter are located at the belly rather than along the body sides as in the Haemadipsidae proper. All Xerobdellidae have three jaws. Haemadipsidae probably originated in the

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

, more than 150

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

(mya). The diversification of the large

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

n genus '' Haemadipsa'' probably did not take place until the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

, about 50 mya. Because members of this family are terrestrial, feed on vertebrate blood, and digest blood meals fairly slowly, they are used in invertebrate-derived environmental DNA ( eDNA) research. By extracting DNA from leech guts and sequencing vertebrate-specific genes, it is possible to identify which vertebrate the leech in question has fed upon, and therefore what animals are in the surrounding habitat. This methodology can be complementary to

camera trap A camera trap is a camera that is automatically triggered by motion in its vicinity, like the presence of an animal or a human being. It is typically equipped with a motion sensor—usually a passive infrared (PIR) sensor or an active infrared ...

biodiversity surveys, which often undercount smaller animals.

Genera

As of April 2025, the following genera are assigned to this family: # ''

'' (synonyms include ''Geobdella'') # '' Diestecostoma'' # '' Domanibdella'' # '' Haemadipsa'' # '' Hygrobdella'' # '' Idiobdella'': monotypic ''I. seychellensis'' # '' Keibdella'' # '' Leiobdella'' # '' Malagabdella'' # '' Mesobdella'' # '' Neoterrabdella'' # '' Nesophilaemon'' # '' Philaemon'' # '' Planobdella'' # '' Sinospelaeobdella'' # '' Tritetrabdella''

References

External links

Japanese Mountain Leech video
on

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Leeches Arhynchobdellida Annelid families Taxa described in 1893 Taxa named by Raphaël Blanchard {{Improve categories, date=March 2025