Land Leeches Research Articles

Identification and functional characterization of multiple haemadins and an oligomeric decorsin in the Asian land leech Haemadipsa interrupta

Haematophagous leeches rely on a broad variety of bioactive compounds to secure a sufficient blood meal from their vertebrate prey. Both the primary (platelet aggregation) and secondary (blood coagulation) haemostasis are the main targets of action. The platelet aggregation inhibitor decorsin was first described in the North American leech, Macrobdella decora Say, 1824, whereas the bivalent thrombin inhibitor hirudin was originally identified in the European medicinal leech, Hirudo medicinalis Linnaeus, 1758. Hirudin blocks both the catalytic site and the fibrinogen-binding site (exosite I) of thrombin. Haemadin of the Indian land leech Haemadipsa sylvestris Blanchard, 1894, is also a highly efficient bivalent thrombin inhibitor but blocks exosite II of thrombin. So far, only the archetypal form of haemadin from H. sylvestris has been purified and functionally characterized, and two putative haemadins have been identified in the salivary transcriptome of Haemadipsa interrupta Moore, 1835, a terrestrial leech inhabiting mainly the Malayan peninsula. Here, we describe the identification of ten additional putative haemadins in the transcriptomic data set of H. interrupta, first generated by another study. Furthermore, we identified a putative oligomeric decorsin, which represents the first finding of this anticoagulant in a haemadipsid leech. Both the putative decorsin and a selection of haemadins were expressed, purified, and functionally characterized. The putative haemadins displayed a broad spectrum of thrombin-inhibitory potencies, whereas the putative oligomeric decorsin was indeed a weak inhibitor of platelet aggregation.

In vitro assessment of Ethanolic extracts from specific herbs on controlling aquatic leech (Tyrannobdella rex) and land leech (Philobdella sp.) infestation in Mithun (Bos frontalis)

Leech infestation poses a significant threat to Mithun (Bos frontalis) in the north-eastern region of India, leading to various health issues and potential fatality. To address this pressing concern, we conducted a comprehensive research study aimed at assessing the efficacy of herbal plant extracts against aquatic leeches, particularly Tyrannobdella rex, and land leeches of the Philobdella sp. Our investigation involved the evaluation of six distinct plant extracts, with a focus on their ability to combat leech infestation. The results of our study revealed that among the various plant extracts tested, only the ethanolic extracts of soapnut (Sapindus mukorossi) and tobacco (Nicotiana tabacum) exhibited notable effectiveness in combating aquatic leeches. At a concentration of 5%, these extracts displayed significant lethality, with soapnut extract achieving a remarkable kill time of 6.0 ± 0.40 min, while tobacco extract showed a kill time of 31.5 ± 1.32 min. In the case of land leeches, tobacco extract proved to be highly efficient, with an average kill time of 1.5 ± 0.28 min at a 5% concentration. Soapnut extract also exhibited effectiveness against land leeches, albeit with a slightly longer kill time of 14.25 ± 1.10 min at the same concentration. Additionally, Litsea grass oil (Litsea cubeba) demonstrated promising efficacy against both aquatic and land leeches, suggesting its potential as a versatile leech control agent. These compelling findings have significant implications for the management and control of leech infestation among Mithun populations. By identifying and harnessing the leech-repelling properties of soapnut, tobacco, and Litsea grass oil, this research offers practical and environmentally friendly solutions for mitigating the adverse effects of leech infestation. Furthermore, the insights gained from this study pave the way for the development of innovative strategies to safeguard the health and well-being of Mithun in the future.

A new checklist of Slovenian leeches (Hirudinea: Euhirudinea): In memory of Boris Sket (1936–2023)

The new (as of 2023) checklist of Slovenian leeches (Euhirudinea) contains 33 species, which represents a 44% increase since the last published inventory in 2003. Notable new entries include Placobdella costata found parasitizing on European pond turtles, the marine fish leech Trachelobdella lubrica from the Slovenian Adriatic coast, the semi-terrestrial Haemopis elegans, the terrestrial Xerobdella praealpina – making Slovenia possibly the only country with confirmed occurrence of all three European land leeches – and a new, still undescribed highly troglomorphic cave leech from a deep Dinaric cave. The number of freshwater fish leeches is underwhelmingly low: two. This, and several unresolved taxonomic questions in erpobdellids suggest that more faunistic and taxonomic work is needed and that the list of Slovenian leech species is far from concluded. The authors dedicate this contribution to their teacher, Prof. Boris Sket (1936–2023), a leading figure in biodiversity research in the Dinaric Karst, including leeches and cave life.

Spermatogenesis and spermatozoon ultrastructure in the jawed bloodfeeding land leechHaemadipsa japonica (Hirudinida: Hirudiniformes) from Japan

Ben Ahmed R., Nakano T., Piątek J., Krzyzczyk R., Świątek P. 2023. Spermatogenesis and spermato- zoon ultrastructure in the jawed bloodfeeding land leech Haemadipsa japonica (Hirudinida: Hirudiniformes) from Japan Folia Biologica (Kraków) 71 : 207-220. The aim of this study is to describe spermatogenesis and spermiogenesis in the jawed sanguivorous land leech Haemadipsa japonica Whitman, 1886, for the first time, using both light and electron microscopy. Spermatogenesis occurs within testisacs, where numerous cysts (clusters) of interconnected spermatogonia, spermatocytes and spermatids freely float in the fluid. In a given cyst, the interconnected germ cells develop in synchrony, i.e.spermatogonial cysts, and cysts with spermatocytes or spermatids can be observed. During spermiogenesis, the spermatids transform into typical hirudinid filiform mature spermatozoa. The ultrastructure of H. japonica spermatozoa is broadly similar to that already described for Haemadipsa zeylanica. The sperm has an anterior and a posterior acrosome, an elongated nucleus with two different morphological regions (an apical corkscrew-shaped region and a basal twisted column-shaped region), a single straight mitochondrion (midpiece) enclosed by a sheath of electron-dense material, and a flagellum with a prominent central sheath arrangement followed by a tapering appendage. A comparison with the previously described spermatozoa from other Clitellata species reveals that the greatest resemblance is to Hirudiniformes.

Concordant genetic structures of sika deer and Japanese land leeches suggest that the current range expansion of Haemadipsa japonica is dependent on sika deer migration: A case study from Tochigi Prefecture, Japan

AbstractHaemadipsa japonica is a Japanese land leech that feeds on the blood of host animals, mainly the sika deer (Cervus nippon). The distribution of H. japonica has expanded since the 1990s, possibly due to sika deer population increases. Haemadipsa japonica populations were found in the northern and southern regions of Tochigi Prefecture, central Japan. Previous investigations reported that these populations are genetically differentiated between the north and south, although the sika deer distribution extends throughout the northern and southern regions. We hypothesized that the migration of sika deer might be limited, thus maintaining the two H. japonica genetic groups and restricting its range expansion. We evaluated this hypothesis by investigating the genetic structure of the mitochondrial DNA (mtDNA) and nuclear microsatellites (nSSR) of sika deer samples collected from Tochigi Prefecture and from H. japonica bloodmeal samples (invertebrate‐derived DNA; iDNA). The sika deer mtDNA presented two haplotypes (G‐ and A‐haplotypes) without a clear genetic structure. Conversely, the sika deer nSSR analysis indicated clear genetic differentiation between deer in the northern and southern regions, corresponding to the two H. japonica genetic groups. This indicates that sika deer movement is restricted to narrow regions in Tochigi Prefecture. Therefore, we conclude that the current H. japonica expansion in the prefecture likely depends on the migration of sika deer, only occurring within the northern and southern regions, even though this is driven by sika deer migration.

Ecology and Biology of the Rare Endemic Land Leech Xerobdella anulata (Xerobdellidae)

The genus Xerobdella contains three species of land leeches confined to the Palearctic region, one of which is X. anulata (Autrum, 1958), an exceptionally rare endemic of the Dinaric Alps. In the current study, we provide new data and a literature overview on this rarely encountered species, presenting its currently known distribution, providing additional data on its morphology and, for the first time, presenting comprehensive data on its habitat preferences and seasonal dynamics. Additionally, we provide novel DNA barcodes for the Dinaric land leech and compare the obtained sequences with the related X. lecomtei. Altogether, 22 specimens of X. anulata were collected using pitfall traps in three habitat types: managed forests with adjacent meadows and a primeval forest in the Dinaric Alps of Croatia. We report the first finding of X. anulata in open habitats, which harbored most of the specimens. Our findings show that X. anulata exhibits surface activity, highlighting the effectiveness of pitfall traps in sampling such elusive taxa, with perspectives for future morphological, phenological and even molecular research.

Characterization of the complete mitogenome of a land leech, Haemadipsa crenata Ngamprasertwong (Arhynchobdellida: Haemadipsidae)

Land leeches of genus Haemadipsa (Family Haemadipsidae) are widely distributed in South East Asia. Haemadipsa crenata Ngamprasertwong is a blood-feeding species firstly reported from Thailand. A complete mitochondrial genome of H. crenata was characterized in this study for further genetic exploration on land leech. The reads were assembled into a circular mitogenome of 14,725 bp in length. The AT content of H. crenata mitogenome is 76.79%. The annotated mitogenome contains 22 tRNAs, 2 rRNAs, and 13 protein-coding genes (PCGs), and the structure of PCG open reading frames was confirmed. Finally, the phylogenetic relationship of H. crenata and other leech species were reconstructed using mitogenomes.

Acute Lymphangitis after a Land Leech Bite.

Acute Lymphangitis after a Land Leech Bite.

Neglected rare human parasitic infections: Part IV: Hirudiniasis

Among all species of leeches, only true leeches especially jawed leeches are known to attack humans. Thesespecies are either freshwater or land dwellers. Freshwater leeches of medical importance may be dividedinto two groups: leeches which attack the mucous membranes (endoparasites), and those that attackthe skin (ectoparasites). Some species of the former group have been incriminated in causing halazoun,while many species of the latter group were used in bloodletting. Leeches may be potential transmitters ofhuman pathogens. The land leeches are much less fearsome than the aquatic leeches. However, the harmwhich land leeches cause to man and his domestic animals may be such that some infested foci becomealmost uninhabitable. This review summarizes current knowledge on the public health significance oftrue leeches as human parasites and their medical uses, and the recommended methods of preventionand control.

Appearance of Granuloma and Prurigo Pigmentosa after Land Leech Bites

Appearance of Granuloma and Prurigo Pigmentosa after Land Leech Bites

Sika deer presence affects the host-parasite interface of a Japanese land leech.

Since the 1990s, increasing populations of a blood feeding land leech (Haemadipsa japonica) have become a serious issue in several Japanese prefectures, and it may be caused by the increases in sika deer (Cervus nippon) populations seen over the last quarter of the century. Therefore, this study aimed to reveal the host animal species of H. japonica using iDNA (vertebrate DNA isolated from invertebrates) and to test the hypothesis that the increasingly widespread distribution of sika deer results in increased H. japonica populations through changes to the host–parasite interface. We amplified mitochondrial DNA 16S ribosome RNA fragments from iDNA isolated from the blood clots of H. japonica collected across Japan. We identified 17 host animal species, including four orders of Mammalia (Carnivora, Artiodactyla, Rodentia, and Lagomorpha) and two orders of Amphibia (Caudata and Anura). The sika deer was the dominant host species of H. japonica. Additionally, the host animal species composition of H. japonica differed according to the presence or absence of sika deer. In the sites where sika deer were not found, Anura (frog) species were the most commonly identified hosts of H. japonica. These results suggest that the increases in H. japonica populations might have occurred via a change in host preference to sika deer. This change might be driven by the increases in sika deer populations and subsequent increase in the frequency that H. japonica uses the sika deer as easy prey, as well as by sika deer providing more reproductive energy per blood meal than blood meal from frog species. The present study suggests that a more widespread distribution of sika deer resulted in an increase in H. japonica through a change in the host–parasite interface. Therefore, management that focuses on decreasing sika deer populations would likely be an effective method for the reduction of H. japonica populations.

ATTITUDES TOWARDS CATCHING AND KILLING THE YAMABIRU (LAND LEECH) IN THE TENRYU AREA, JAPAN

Recently, yamabiru, or land leeches (Haemadipsa zeylanica japonica), have proliferated in prefectures across Japan. Since it is unlikely that they will disappear from the living spaces, fields, and forests in which humans live and work, people living in the new contact zones have devised methods to coexist with them. The field research was conducted in 2017 and 2018 in C Township in the Tenryu area. Like many rural areas in Japan, C Township is facing the challenges of depopulation and ageing, and is home to a group of residents who aim for local revitalization. The participatory observation of leech-catching, an activity practiced by the group members who dare to use their hands to kill yamabiru instead of chemicals, provides several implications regarding ethical attitudes and the role of the human body. This paper argues that the members do not behave as victims suffering from the damage caused by yamabiru and do not kill them out of anger or discomfort. Instead, by behaving as an assailant and seeking out the concrete feeling of killing by direct contact, the members attempt to control their disastrous impact on other creatures and the environment. This behavior invites us to pay closer attention to the role of the human body and of bodily interaction as a sensory tool to coexist with other creatures in the Anthropocene, an era full of risks and uncertainty

An American Terrestrial Leech

Our common land leech was first obtained by me in April, 1876, at Normal, McLean County, Illinois, where it was dug up in a house garden, about a dozen rods from the nearest rivulet. An example sent the following year to Prof. A. E. Verrill, with some remarks on its superficial characters, was by him identified provisionally and with some hesitation as his Semiscolex grandis, originally described* from three aquatic individuals obtained from Lake Huron, Lake Superior, and West River, Connecticut. I have now, however, fifty-six specimens of this leech, all from the earth in Central Illinois, some of them half a mile or more from water, and representing collections made at different times from April, 1876, to June, 1890 ; while, on the other hand, it has not once occurred in the course of a large amount of aquatic work done in the same regions during these fifteen years. It has, moreover, constant characters which clearly distinguish it from Semiscolex qrandis as far as one may judge by a comparison with Verrill's description, and I do not doubt that it is distinct.

Nuclear microsatellite and mitochondrial DNA analyses reveal the regional genetic structure and phylogeographical history of a sanguivorous land leech, Haemadipsa japonica, in Japan.

Recent molecular studies have indicated that phylogeographical history of Japanese biota is likely shaped by geohistory along with biological events, such as distribution shifts, isolation, and divergence of populations. However, the genetic structure and phylogeographical history of terrestrial Annelida species, including leech species, are poorly understood. Therefore, we aimed to understand the genetic structure and phylogeographical history across the natural range of Haemadipsa japonica, a sanguivorous land leech species endemic to Japan, by using nine polymorphic nuclear microsatellites (nSSR) and cytochrome oxidase subunit one (COI) sequences of mitochondrial DNA (mtDNA). Analyses using nSSR revealed that H. japonica exhibited a stronger regional genetic differentiation among populations (G'ST = 0.77) than other animal species, probably because of the low mobility of land leech. Analyses using mtDNA indicated that H. japonica exhibited two distinct lineages (A and B), which were estimated to have diverged in the middle Pleistocene and probably because of range fragmentation resulting from climatic change and glacial and interglacial cycles. Lineage A was widely distributed across Japan, and lineage B was found in southwestern Japan. Analyses using nSSR revealed that lineage A was roughly divided into two population groups (i.e., northeastern and southwestern Japan); these analyses also revealed a gradual decrease in genetic diversity with increasing latitude in lineage A and a strong genetic drift in populations of northeastern Japan. Combined with the largely unresolved shallow polytomies from the mtDNA phylogeny, these results implied that lineage A may have undergone a rapid northward migration, probably during the Holocene. Then, the regional genetic structure with local unique gene pools may have been formed within each lineage because of the low mobility of this leech species.

Vampire in the darkness: a new genus and species of land leech exclusively bloodsucking cave-dwelling bats from China (Hirudinda: Arhynchobdellida: Haemadipsidae).

Land leeches in the family Haemadipsidae are mostly from the humid tropical rainforest habitats and habitually take blood from the body of human and other animals. In the present study, we report a new species, Sinospelaeobdella wulingensis sp. n., from caves in the northern subtropical Wuling Mountains of central-south China that feeds blood exclusively on cave-dwelling bats. Based on morphological characteristics, COI gene sequence divergence, and phylogenetic analysis, a new genus Sinospelaeobdella gen. n. is established for the new species, to which a previously described species Haemadipsa cavatuses Yang et al., 2009 is transferred as S. cavatuses comb. n. We also provided extended discussion on phylogenetic relationship within the "Tritetrabdellinae" clade uncovered in a previous study, DNA taxonomy, morphological and behavioral adaptions, biogeography, and possible involvement of Sinospelaeobdella gen. n. in bat transmitted diseases of public concerns.

Analysis of genetic variation in mitochondrial cytochrome c oxidase subunit 1 between Haemadipsa japonica in Japan and land leeches worldwide

Haemadipsa japonica is the most common land leech species found in Japan. It has been considered to possess genetic variation that limits its habitat range. In the present study, to characterize variation in the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of H. japonica specimens from various locations in Japan, we examined nucleotide sequences of the mitochondrial cox1 gene. We performed PCR of mitochondrial cox1 using 10 H. japonica specimens and compared the result with those of land leeches from around the world using a maximum likelihood (ML) tree. ML tree of H. japonica in Japan showed significant differences between cox1 sequences of specimens from Yakushima and other regions of Japan. ML tree of land leeches from around the world revealed that H. japonica had the closest relationship with H. picta from Borneo.

Adhesion principle of land leech and its application to sucker design

Adhesion principle of land leech and its application to sucker design

Jalaukavacharan (Indian medicinal leech application) in the management of Raynaud’s disease- A single case Report

In Ayurveda , Sushruta has described the uses of Jalauka (medicinal leech) for the treatment of various medico-surgical disorders. About 700 leech species were identified and among them only 5 leeches are used for medicinal purpose. In Ayurveda, 2 varieties of Jalauka are found i.e. poisonous group ( Savisha ) and non-poisonous group ( Nirvisha ) while in modern science, poisonous leech are known as stinging land leeches ( Hemadipsapicta and Hemadipsa ornate) . The species Hirudomedicinalis is commonly used for therapeutic purpose which is a NirvishaJalauka. During the process of sucking, leeches secrete various biological enzymes in to the blood stream through its saliva. Hirudin is one important component which acts as anti-coagulant. In addition to that several other properties are found in leech saliva like anesthetic, antibiotic, analgesic etc. Therefore it is advised to use in ischemic, inflammatory conditions, skin grafting, chronic fatigue, pain, non-healing ulcers, etc. In this case report, female patient aged 80 years diagnosed of having Raynaud’s disease with complaints of gangrenous changes in left digital phalanges (three fingers), swelling and pain in forearm since 20 days. Three leeches were applied in each digit of gangrenous part. Total three setting once in every week was done. After 1 st sitting of Jalauka application pain and swelling was reduced. After second sitting the line of demarcation was developed and the necrosed part was dried up. After third sitting all necrosed part was sloughed out without surgical debridement. This single case manifests that gangrenous digit due to Raynaud’s disease can be managed with Jalauka application.

Information on inhabitation of a land leech species (Haemadipsa japonica) on the Tanzawa Mountains before 1945 obtained from mountaineering literature

Information on inhabitation of a land leech species (Haemadipsa japonica) on the Tanzawa Mountains before 1945 obtained from mountaineering literature

Characterization of 13 polymorphic microsatellite loci in the Japanese land leech

We developed 13 polymorphic microsatellite loci of the Japanese land leech (Haemadipsa japonica; Haemadipsidea) using an Illumina MiSeq sequencing approach. A total of 42,064 nuclear DNA contigs were filtered for microsatellite motifs, among which 30,873 simple sequence repeat loci were identified. From these sequences, we selected 30 primer sets, and 13 of these loci were successfully amplified. Polymorphism of the 13 loci was tested using 16 individuals sampled from sixteen populations across Japan. The number of alleles and polymorphism information content varied from 5 to 17 and 0.335 to 0.883, respectively, and observed and expected heterozygosity values ranged from 0.143 to 0.875 and 0.349 to 0.893, respectively, indicating that these loci are polymorphic. Furthermore, we established useful multiplex PCR using these loci. The 13 microsatellite loci described in this paper are the first nuclear microsatellite markers for a land leech species.