Glossiphoniidae are the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 called freshwater jawless leeches or glossiphoniids. They are one of the main groups of Rhynchobdellida

Rhynchobdellida

Rhynchobdellida, the jawless leeches, are classified as an order of the Hirudinea. But leech taxonomy and systematics will eventually be revised in due time, not because there are many uncertainties about their phylogeny, but because the major clades of clitellate annelids – and whether the...

, true leech

Leech

Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways...

es with a proboscis. These leeches are generally flattened, and have a poorly defined anterior sucker. Most suck the blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 of freshwater vertebrate

Vertebrate

Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...

s like amphibian

Amphibian

Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...

s and aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 turtle

Turtle

Turtles are reptiles of the order Testudines , characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield...

s, but some feed on the hemolymph

Hemolymph

Hemolymph, or haemolymph, is a fluid in the circulatory system of some arthropods and is analogous to the fluids and cells making up both blood and interstitial fluid in vertebrates such as birds and mammals...

 of invertebrate

Invertebrate

An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s like oligochaetes and freshwater snail

Freshwater snail

A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....

s instead.

Freshwater jawless leeches are remarkable for their parental care, the most highly developed one among the known annelid

Annelid

The annelids , formally called Annelida , are a large phylum of segmented worms, with over 17,000 modern species including ragworms, earthworms and leeches...

s. They produce a membranaceous bag to hold the eggs, which is carried on the underside. The young attach to the parent's belly after hatching and are thus ferried to their first meal.

There is considerable interest in the symbiontic bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 that at least some glossiphoniids carry in specialized compartments of the esophagus

Esophagus

The esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...

 to aid in digesting their meals. Haementeria as well as Placobdelloides have Enterobacteriaceae

Enterobacteriaceae

The Enterobacteriaceae is a large family of bacteria that includes many of the more familiar pathogens, such as Salmonella, Escherichia coli, Yersinia pestis, Klebsiella and Shigella. This family is the only representative in the order Enterobacteriales of the class Gammaproteobacteria in the...

 symbionts, while Placobdella harbours peculiar and independently derived Alpha Proteobacteria.

Systematics and taxonomy

The Theromyzinae are a rather enigmatic subfamily and their relationship to other glossiphoniids has as of yet resisted elucidation. Also, there are several genera of more basal or uncertain position:

• Batracobdella
• Boreobdella
• Marsupiobdella
• Placobdella Blanchard, 1893 - includes Desserobdella Barta & Sawyer, 1990 and Oligobdella Moore
  John Percy Moore
  John Percy Moore was an American zoologist specialising in leeches. He was born at Williamsport, Pa. and was educated at the Central High School of Philadelphia and at the University of Pennsylvania B.S., 1892; Ph.D., 1896), where he was instructor in zoology from 1892 to 1907, assistant...
  
  , 1918, formerly in Glossiphoniinae
• Placobdelloides Sawyer, 1986 - possibly paraphyletic

Ecology and behavior

Some species of the Glossiphoniidae exhibit considerable evidence of parental nurturing.

Certain Glossiphoniidae attack amphibian species. For example, some members of the Glossiphoniidae are known to attack the inner oral cavity of the Rough-skinned Newt

Rough-skinned Newt

The rough-skinned newt is a North American newt known for its strong poison.- Toxicity :Many newts produce toxins to avoid predation, but the toxins of the genus Taricha are particularly potent...

.

Medical importance

While glossiphoniids do not feed on humans, they are nonetheless of medical interest. As with all blood- or haemolymph-feeding leeches, their saliva

Saliva

Saliva , referred to in various contexts as spit, spittle, drivel, drool, or slobber, is the watery substance produced in the mouths of humans and most other animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands,...

, contains anticoagulant

Anticoagulant

An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...

 compounds which are potentially useful in therapy of some cardiovascular disease

Cardiovascular disease

Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...

s. Antistasin and related inhibitors of thrombokinase a

Factor X

Factor X, also known by the eponym Stuart-Prower factor or as prothrombinase, is an enzyme of the coagulation cascade. It is a serine endopeptidase .-Physiology:...

 such as ghilanten, lefaxin and therostatin have been derived from Haementeria species and Theromyzon tessulatum. These substances also may prevent certain tumor

Tumor

A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

s from metastasizing

Metastasis

Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...

. Also from Haementeria are the fibrin stabilizing factor a

Factor XIII

Factor XIII or fibrin stabilizing factor is an enzyme of the blood coagulation system that crosslinks fibrin.- Function :Factor XIII is a transglutaminase that circulates in the plasma as a heterotetramer of two catalytic A subunits and two carrier B subunits...

 inhibitor tridegin, a platelet

Platelet

Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes.  The average lifespan of a platelet is normally just 5 to 9 days...

 adhesion

Adhesion

Adhesion is any attraction process between dissimilar molecular species that can potentially bring them in close contact. By contrast, cohesion takes place between similar molecules....

 inhibitor (LAPP), and the fibrinogen

Fibrinogen

Fibrinogen is a soluble plasma glycoprotein, synthesised by the liver, that is converted by thrombin into fibrin during blood coagulation. This is achieved through processes in the coagulation cascade that activate the zymogen prothrombin to the serine protease thrombin, which is responsible for...

-dissolving enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s hementin

Hementin

Hementin is an anticoagulant protease from the salivary glands of the giant Amazon leech . Hementin dissolves a type of platelet rich blood clot which cannot be dissolved by other well used drugs like streptokinase and urokinase....

 and hementerin. T. tessulatum also yields therin, theromin and tessulin, which inhibit protease

Protease

A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....

 activity. Ornatins, which are antiplatelet glycoprotein

Antiplatelet drug

An antiplatelet drug is a member of a class of pharmaceuticals that decrease platelet aggregation and inhibit thrombus formation...

 IIb-IIIa antagonist

Receptor antagonist

A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...

s, were discovered in Placobdella ornata, and several species have yielded hyaluronidase

Hyaluronidase

The hyaluronidases are a family of enzymes that degrade hyaluronic acid.In humans, there are six associated genes, including HYAL1, HYAL2, HYAL3, and PH-20/SPAM1.-Use as a drug:...

s.