Hirudinea

This three-volume work provides a complete study of this well-known group of animals, dealing with every level of their biological organization, from the molecular to the zoological.
    The leech, once so prominent in the history of medicine, is again being used widely in modern hospitals, especially in microsurgery. Revival in the use of leeches coincides with recent revelations about the rich diversity of pharmacologically active peptides secreted by the leech, including the powerful anticoagulant Hirudin which was discovered in 1884. The author who has studied  leeches extensively for many years, documents for the first time the scientific and biological rationale underlying the medical use of leeches and concludes that there was a nucleus of truth behind their use in previous centuries.
    In recent years the leech has been the subject of much neurobiological research, but such research has tended to emphasize the neurophysiological aspects. This book gives an authoritative account of leech neurobiology from the biological viewpoint, with emphasis on the neuronal basis and the evolution of leech behaviour.
    The book takes up Manton's controversial thesis that insects, myriapods and onychophorans constitute a new phylum (Uniramia) unrelated to the Crustacea. He also significantly extends the argument by proposing that leeches are also allied to the Uniramia. This proposal is a major intrusion into the traditional classification of the animal kingdom, and as such is likely to gain considerable attention.
    A 'key' to the leeches of each zoogeographical region of the world and an extensive bibliography (volume 3) are included.
    The diverse and wide-ranging nature of the book should make it of interest to research workers and students in various disciplines, particularly medicine, molecular biology, neurobiology, zoology and marine biology.
    Volume 1:    0 19 857377 4,  430 pages, 170 illustrations
    Volume 2:    0 19 857622 6,  430 pages, 170 illustrations
    Volume 3:    0 19 857623 4,  240 pages

The author surveys a number of morphological traits found in the Hirudinea which may indicate a phylogenetic link with arthropods, especially Insects/ hexapoda, and other Uniramia. Of special interest in this context is the presence of pre-lobopodia.

A summary of known terrestrial leeches of the United States, with a brief account of terrestrialism in leeches generally. The true terrestrial, borrowing leeches have distinctive morphology, including large body size, firmness of body, prolonged head region and reduction of caudal sucker. In the United States there are two species of terrestrial leeches, found in southern and central states. These include Haemopis oenops Grube 1871 (a new name for Haemopis terrestris Forbes 1890, based on rediscovery of an early specimen from Mississippi in the Berlin Museum, predating Forbes's account by nearly 20 years). The second species, described as recently as 1976, is Haemopis septagon, a relict species from coastal Carolinas and Virginia.

ABSTRACT: Eight species of marine and freshwater leeches are reported from Puerto Rico, five of which are new to the Puerto Rican fauna. Additional observations of leeches from
other Caribbean islands are reported, along with a key to the nine known species of the Caribbean region, excluding Trinidad. Leeches of the Caribbean

First southern state to be surveyed for its leeches. The leech fauna is rich and diverse, the paper recording 15 species in 4 families, including one marine leech Pontobdella macrothela. The most common was the eropobdellid Mooreobdella microstoma

ABSTRACT: A fossil worm-like organism, ca. 0.5 mm long, showing cuticle, gut and setae. is contained in the solid part of the wall of a clitellate cocoon from the Early Cretaceous (Barremian). It is interpreted as having been entrapped and embedded in the intitially viscous cocoon secretion which solidified and thus prevented decay. Size, shape, posture, and an unsegmented but annulated cuticle with irregularly distributed setae have led to the identification of the fossil as a nematode. described as Captivonema cretacea gen. et sp. n., of uncertain family and order affinity. Fossil association end mode of preservation indicate a free-living life habit in damp plant litter.

In this study 14 species of marine leeches (Piscicolidae) are reported. These are divided geographically into  northern and southern species, and ecologically into brackish water and high salinity species. Notice is made of Cape Hatteras as a divide between northern and southern species.

Novel hirudin variants isolated from the leech Hirudinaria manillensis, a leech more specialized
for mammalian parasitism, are described. Isolation of antithrombin polypeptides was performed by
ion-exchange chromatographies followed by an affinity chromatography step on immobilized thrombin.
The major active component, antithrombin polypeptide peak 2 (HM2), and a second polypeptide,
named HM1, were purified to homogeneity and their complete amino acid sequences were
determined. The protein structure of the two hirudin variants include 64 amino acids with 6 cysteine
residues at highly conserved positions. Comparison of the amino acid sequences of HM1 and HM2
with other known hirudins shows differences mainly in the central part and in the C-terminal region
of the polypeptides. Particularly significant is the lack of a sulfated tyrosine residue in the Cterminal
portion of the molecule which is replaced by aspartic acid.
Polymerase chain reaction cloning techniques were used to isolate and characterize the cDNAs
and determine the genomic structures of these hirudin-like polypeptides. The cDNA clones coding
for the two variants indicate the expression of pre-hirudins of 84 amino acids where the first 20
residues constitute the signal peptide required for extracellular secretion. The leader sequence appears
to be highly conserved for both isoforms and shares a complete similarity with the partial
hirudin variant 2 (HV2) signal peptide sequence previously reported.
The HM1 and HM2 gene fragments show the presence of four exons: the first one corresponding
to a 20-amino-acid signal peptide while the other three exons share the full primary structure of the
antithrombin polypeptides.
HM2 was also efficiently produced in recombinant Escherichia coli by expressing a periplasmic
construction containing the synthetic gene.

"The Hirudinea fauna in northeast Brandenburg, a part of the young moraine region of northeast Germany, was investigated for the first time. Between April 2006 and May 2008 in the study area 16 species were found. The most species rich fauna was detected in permanent water bodies. Erpobdella octoculata is the most common species followed by E. nigricollis. Only 7 species were detected in temporary infield kettle holes with Dina lineata as characteristic species. Populations of the endangered medicinal leech Hirudo medicinalis were found in some semipermanent kettle holes. Records of the leech fauna beginning with data published by Kalbe (1964-1966) and including so far unpublished data are summarised in a preliminary
checklist of Hirudinea of Brandenburg comprising 24 species."

The bite of the Amazon leech Haementeria ghilianii is not associated with prolonged bleeding, and does not secrete anticoagulant hirudin. This studies looks at the function of hementin, the fibrinogenolytic enzyme secreted by this species. Conclusion it prevents clotting of blood in its long tubular proboscis.
ABSTRACT: The giant Amazon leech Haementeria ghilianii feeds by inserting an exceedingly long tubular proboscis (up to 10 cm) deep into its mammalian host. The wound from its bite is not associated with prolonged bleeding because all antihaemostatic factors, including the fibrinogenolytic enzyme hementin, appear to be secreted exclusively into the lumen of the proboscis. It is in this narrow lumen that blood first comes into contact with hementin, the secretion of which is under neuronal control from the brain. During feeding, about 15 ml of blood are sucked through the proboscis at the rate of approximately 0.14 ml/min. A complete passage of blood takes less than 1 min, much faster than the approximately 6 min needed for coagulation (fibrin formation). Therefore, it is unlikely that hementin functions in the proboscis simply to prevent fibrin formation. Of greater risk is platelet aggregation which can occur within 1-2 min. The formation of a platelet-rich clot within the proboscis could make the proboscis non-functional. Hementin's unique ability to dissolve platelet-rich clots offers a way of restoring blood flow through the proboscis. Hementin is able to disaggregate platelets by breaking the fibrinogen crosslink between platelets. Hementin's unique cleavage site in the connector region of platelet-bound fibrinogen is thought to be a most effective mechanism for eliminating the crosslinking.

The occurrence of Helobdella triserialis associated with two freshwater snails, Pomacea diffusa and Pomacea canaliculata, is recorded for the first time in Brazil. We also point out the new association between the leech and P. diffusa in nature.

The salivary glands of the Amazon leech Haementeria ghilianii (Glossiphoniidae) contain an enzyme, named herein Hementin, which degrades fibrinogen and fibrin. This proboscis leech does not contain the antithrombin hirudin and in this respects differs fundamentally from the jawed medicinal leech Hirudo medicinalis (Hirudinidae)

The occurrence of Helobdella triserialis associated with two freshwater snails, Pomacea diffusa and Pomacea canaliculata, is recorded for the first time in Brazil. We also point out the new association between the leech and P. diffusa in nature.

In this study the nature of the anticoagulant found in the salivary glands of the proboscis leech, the giant Amazon leech Haementeria ghilianii is investigated. The enzyme named herein HEMENTIN dissolves preformed clots. It catalyzes the proteolytic degradation of fibrinogen and fibrin. The salivary glands of H. ghilianii do not have HIRUDIN, an inhibitor of human and bovine thrombin, from the jawed medicinal leech Hirudo medicinalis. Therefore, Haementeria ghiianii prevents coagulation of its host's blood through a fibrinogenolyitc mechanism which is entirely different from that of Hirudo medicinalis

The author takes a reflective look at medical history and what we can learn from it. Focus is on the history of the medicinal leech and the significance, if any, of bloodletting through the ages. Other bloodsucking animals, such as mosquitoes, fleas, ticks and flies, may have something to tell us about drug discovery.

ABSTRACT: In this paper the effectiveness of the so-called American medicinal leech Macrobdella decora in overcoming human haemostasis is compared to that of the European medicinal leach Hirudo medicinalis. Thrombin-clotting times indicated that M. decora prevents coagulation of human blood by means of anti-thrombin activity. Our findings suggest that its role is similar to that of hirudin. In human volunteers, the duration of bleeding from the bite of M. decora (mean = 73 min; n = 18) is significantly shorter than H. medicinalis (mean = 600 min; n = 15). The mean concentration of anti-thrombin units in each specimen of M. decora and H. medicinalis is 100 and 285 AT-U, respectively. These findings support the concept that H. medicinalis is more advanced in terms of haematophagous predation. Despite similar feeding durations by both species of leech (means = 68 min and 70.5 min by M. decora and H. medicinalis, respectively), the mean increase in body weight of M. decora was only 58% compared to 460% in H. medicinalis.

ABSTRACT: The local distribution and relative abundance of the leeches of the E. S. George Reserve, located in southeastern Michigan, were investigated. Fourteen species of leeches were found on the Reserve, five of which are new to Michigan and one is new to the United States.

ABSTRACT: Previously enigmatic, ovoid to sac-like fossils of organic, acid resistant substance which are common components of leaf cuticle and megaspore assemblages in limnic and terrestrial palaeoen- vironments are identified as cocoons of clitellates. They have been recorded for a long time by palaeobotanists and palynologists, particularly in the Mesozoic, and have been variously interpreted as being of megaspore, seed, or algal origins, although convincing homologues were lacking. The fossils agree in basic wall construction with cocoons of clitellates, and particularly with certain members of the Hirudinea. A clitellate affinity is further supported by a possible segmentation, their consistently non-marine occurrence, evidence for predation, and an example of amber-like inclusion of alien structures in the cocoon wall which indicates the presence of secretion. As a consequence of the new interpretation, two taxa established under the botanical code of nomenclature for such fossils, namely Burejospermum crassitestum Krassilov and Dictyoth- ylakos pesslerae Horst, are transferred to the zoological kingdom and classified under Clitellata (phylum Annelida), along with two new taxa, D. spitsbergensis sp.n. andPilothylakospilosus gen. et sp.n. With the present interpretation a consistent Mesozoic record is documented for clitellates, a group of softbodied, basically freshwater and terrestrial animals of which there was until now nearly no fossil record.

Leech hyaluronidase has been purified. It is specific for hyaluronic acid as its substrate, in sharp contrast to lack of specficity for mucopolysaccharides exhibited by mammalian testicular hyaluronidase. Leech hyaluronidase has excellent thermostability: At 50 C it loses no activity for 40 min and retains significant activity after several hours. At 60 C it loses only 25% of its activity after incubation for 5 min. Possible medical use for treatment of eye disorders and as an adjunct to cutaneously injected drugs.

Factors which influence physiological color change in leeches was studied using the Hogben and Slome chromatophore  index. Leeches disperse their pigments in the light and concentrate them in the dark. They do no background adapt but do respond to changes in light intensity. Ligation experiments implicate a neurohormonal mechanism. The response revolved de novo in the Rhynchobdellida (Glossiphoniidae and Piscicolidae).

The marsupial leech Maiabdella batracophila was found on several occasions on the frog Telamatobius sp in the dry northern part of Chile.
Muñoz-Leal, S., Roy T Sawyer and D. González-Acuña (2012). Diagnóstico tentativo de Maiabdella batracophila (Ringuelet, 1980) (Hirudinea: Glossiphoniidae) como ectoparásito en Telamatobius spp. (Anura: Ceratophrydae) en distintas localidades del altiplano chileno. Chilean Herpetological Congress, Santiago, September 2012.

We conclude that Calin, isolated from the saliva of the medicinal leech Hirudo medicinalis, is a specific inhibitor of platelet collagen interaction which may therefore be a useful tool to study contribution of platelet adhesion to collagen and extracellular matrix both in vitro and in vivo.

Leech hyaluronidase (Orgelase) was studied as a potential skin penetration enhancer using human cadaver skin. Results showed there was a twenty-fold increase in flux of metronidazole through the skin compared to controls. Conclusion that leech hyaluronidase has potential as a skin penetration enhancer in vivo.

In Wales [at time of writing this article] the endangered medicinal leech Hirudo medicinalis is known from only one site, near Port Talbot. This paper is to alert naturalists in Dyfed to be on alert for this species in other localities in Wales.

ABSTRACT: Both leech hyaluronidase and bovine testicular hyaluronidase use an arginine residue for substrate binding. However, in addition to the different mechanisms of action of these enzymes they also exhibit distinct substrate specificities. Therefore, although arginine residues are important for substrate binding they appear not to influence substrate specificity

ABSTRACT: The bite of the North American leech Macrobdella decora results in much less prolonged bleeding in fish (8 min; control = 1 min) and amphibians (11.5 min; control = 1.5 min) than in mammals (humans) (73 min; control = 6 min). Coagulation of blood flowing from leech bite wounds is initially prolonged in frogs (4.3 min; control = 2 min) and humans (5.8 min; control = 2.5 min), but gradually returns to normal during the first 10 min after the termination of feeding. Although duration of feeding is similar in fish (mean = 62 min), amphibian (mean = 79 min) and human (mean = 68 min) hosts, the gain in body weight of leeches feeding on fish (mean = 11%) and amphibians (mean = 14%) is much less than those feeding on humans (mean = 58%). Bleeding in a frog heavily infected with the intrathrombocytic yeast Thrombocytozoons ranarum was abnormal from control incisions (>20 min) and from a leech bite wound (>140 min) suggesting impairment of thrombocyte function. This comparative approach to leech — host haematology offers a methodology into understanding the biological context in which the leech antithrombin (hirudin) evolved, as well as the evolution of vertebrate haemostatic mechanisms.

Twenty freshwater, one euryhaline, one terrestrial, and six marine leeches are now known to occur in the Carolinas. Haemopis septagon, the second terrestrial leech discovered in North America, and five aquatic taxa—Placobdella nuchalis, P. translucens, Mooreobdella melanostoma, M. tetragon, and Erpobdella punctata coastalis—are previously undescribed. Specimens of Placobdella papillifera and P. multilineata, are examined in detail. Four additional species—Batracobdella phalera, B. picta, Helobdella elongata and Haemopis marmorata—have been found in the Carolinas for the first time.The distribution of leeches in the Carolinas is determined in part by the boundaries of the three physiographic provinces. Batracobdella picta, Oligobdella biannulata, and Haemopis marmorata occur only in the Appalachian Mountains, while Placobdella nuchalis, P. translucens, Glossiphonia swampina, Batracobdella phalera, Helobdella stagnalis, H. elongata and Macrobdella ditetra were found only in the coastal plain. Along with the physiographic determinants of distribution, there are also north-south factors of interest. The coastal plain species Philobdella gracilis, also found in the piedmont plateau, and Macrobdella ditetra are southern species which reach the northern limit of their range in North Carolina. On the other hand, Batracobdella picta, Erpobdella punctata punctata, Haemopis marmorata, and Macrobdella decora are common northern leeches and reach their southern limit in the area. Still other species—Placobdella nuchalis, Glossiphonia swampina, Oligobdella biannulata, Erpobdella punctata coastalis, Mooreobdella melanostoma, M. tetragon, and Haemopis septagon—appear to be highly localized and are currently known only from the Carolinas, extending into southeastern Virginia in the case of H. septagon (Shelley, 1975).Observations of locomotion and other behaviour in the biannulate leech, Oligobdella biannulata, reveal a lack of muscular activity in the mid-body regions, which may partially explain the significance of the biannulate condition. This species has been found to have more than one desmognathine salamander host in nature.A key to the hirudinifauna of the Carolinas, both known and expected, has been formulated.

Of the 28 leech taxa known from South Carolina, only a few deserve special attention. The marine skate leech Branchellion ravenelii was originally described from Charleston in 1850. It has not been reported from South Carolina since. The 'relict' salamander leech Oligobdella biannulata may be of special evolutionary significance. It has been found in only a few montane localities in South Carolina. A concern for the future of this species is that the range and population levels are unknown and a decline would go undetected. The terrestrial leech Haemopis septagon. Even though it is one of the largest terrestrial invertebrates in the United States its presence was undetected until this year. It lives in the difficult, and poorly studies lowland swamps of coastal NC, SC and VA. Only one record is known from South Carolina.  Only one record of the frog leech Macrobdella decora is known from South Carolina.

The common fish leech Illinobdella moorei is parasitic on the White Catfish Ictalurus in the estuaries of South Carolina. The life cycle of a population of infected catfish was monitored  monthly in the Ashley River, Charleston. At one point in the cycle the leeches transfer to the carapace of blue crabs Callinectes sapidus, where they deposit cocoon.

Marine leeches of South Carolina have been poorly studied. This paper reports the presence of several species, including Calliobdella carolinensis, Myzobdella lugubris on blue crabs, Branchellion ravenelii  on a skate, and Trachelobdella vividus

A summary of recent advances in new pharmacaologically active substances from leeches, mosquitoes, ticks, fleas,vampire bats, flies and other bloodsucking animals. The conclusion is that this is a new potentially useful area for discovering new cardiovascular drugs. 13 pages, 2 tables