Hematophagy

{{short description|Ecological niche involving feeding on blood}} {{about|the consumption of blood by animals|the consumption of blood by humans|Blood as food}} {{redirect|Bloodsucker}} {{redirect|Sanguivore|the album|Sanguivore (album){{!}}''Sanguivore'' (album)}}

[[File:Anopheles stephensi.jpeg|thumb|250px|right|An ''Anopheles stephensi'' mosquito obtaining a blood meal from a human host through its pointed proboscis. Note the droplet of blood being expelled from the engorged abdomen. This mosquito is a malarial vector with a distribution that ranges from Egypt to China.]] [[File:Cimex lectularius.jpg|thumb|A bedbug]] [[File:Blood feeding butterflies 5362.JPG|thumb|Two butterflies of the genus ''Erebia'' sucking fresh blood from a sock]]

'''Hematophagy''' (sometimes spelled '''haematophagy''' or '''hematophagia''') is the practice by certain animals of feeding on blood (from the Greek words αἷμα ''{{lang|grc-Latn|haima}}'' "blood" and φαγεῖν ''{{lang|grc-Latn|phagein}}'' "to eat"). Since blood is a fluid tissue rich in nutritious proteins and lipids that can be taken without great effort, hematophagy is a preferred form of feeding for many small animals, such as worms and arthropods. Some intestinal nematodes, such as Ancylostomatids, feed on blood extracted from the capillaries of the gut, and about 75 percent of all species of leeches (e.g., ''Hirudo medicinalis'') are hematophagous. The spider ''Evarcha culicivora'' feeds indirectly on vertebrate blood by specializing on blood-filled female mosquitoes as their preferred prey.<ref>{{cite journal | pmid=22032682 | year=2012 | last1=Jackson | first1=R. R. | last2=Nelson | first2=X. J. | title=Evarcha culicivora chooses blood-fed Anopheles mosquitoes but other East African jumping spiders do not | journal=Medical and Veterinary Entomology | volume=26 | issue=2 | pages=233–235 | doi=10.1111/j.1365-2915.2011.00986.x | hdl=10092/9753 | s2cid=25520447 | hdl-access=free }}</ref> Some fish, such as lampreys and candirus; mammals, especially vampire bats; and birds, including the vampire finch, Hood mockingbird, Tristan thrush, and oxpeckers, also practice hematophagy.

==Mechanism and evolution==

Hematophagous animals have mouth parts and chemical agents for penetrating vascular structures in the skin of hosts, mostly of mammals, birds, and fish. This type of feeding is known as phlebotomy{{Citation needed|date=April 2026}} (from the Greek words, ''phleps'' "vein" and ''tomos'' "cutting").

Once phlebotomy is performed (in most insects by a specialized fine hollow "needle", the proboscis, which perforates skin and capillaries; in bats by sharp incisor teeth that act as a razor to cut the skin), blood is acquired either by sucking action directly from the veins or capillaries, from a pool of escaped blood, or by lapping (again, in bats).{{Citation needed|date=April 2026}} To overcome natural hemostasis (blood coagulation), vasoconstriction, inflammation, and pain sensation in the host, hematophagous animals have evolved chemical solutions, in their saliva for instance, that they pre-inject—and anesthesia and capillary dilation have evolved in some hematophagous species. Scientists have developed anticoagulant medicines from studying substances in the saliva of several hematophagous species, such as leeches (hirudin).<ref>{{Cite journal |last=Warkentin |first=Theodore E. |date=2004 |title=Bivalent direct thrombin inhibitors: hirudin and bivalirudin |journal=Best Practice & Research. Clinical Haematology |volume=17 |issue=1 |pages=105–125 |doi=10.1016/j.beha.2004.02.002 |issn=1521-6926 |pmid=15171961}}</ref>

Hematophagy is classified as either ''obligatory'' or ''facultative''. Obligatory hematophagous animals cannot survive on any other food. Examples include ''Rhodnius prolixus'',<ref name=":0">{{Cite journal |last1=Ouali |first1=Radouane |last2=Bousbata |first2=Sabrina |date=2025 |title=Rhodnius prolixus (kissing bug) |journal=Trends in Parasitology |volume=41 |issue=11 |pages=1064–1065 |doi=10.1016/j.pt.2025.06.014 |issn=1471-5007 |pmid=40664521 |hdl=2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/393679 |hdl-access=free }}</ref> a South American assassin bug, and ''Cimex lectularius'', the human bed bug.{{Citation needed|date=April 2026}} Facultative hematophages, meanwhile, acquire at least some portion of their nutrition from non-blood sources in at least one of the sexually mature forms. Examples of this include many mosquito species, such as ''Aedes aegypti'', whose both males and females feed on pollen and fruit juice for survival, but the females require a blood meal to produce their eggs. Fly species such as ''Leptoconops torrens'' can also be facultative hematophages.{{Citation needed|date=April 2026}} In anautogenous species, the female can survive without blood but must consume blood in order to produce eggs (obligatory hematophages are by definition also anautogenous).

As a feeding practice, hematophagy has evolved independently in a number of arthropod, annelid, nematode and mammalian taxa. For example, Diptera (insects with two wings, such as flies) have eleven families with hematophagous habits (more than half of the 19 hematophagous arthropod taxa).<ref>{{Cite journal |last1=Devilliers |first1=Julien |last2=Warren |first2=Ben |last3=Rosato |first3=Ezio |last4=Kyriacou |first4=Charalambos P. |last5=Feuda |first5=Roberto |date=2025-03-06 |title=Hematophagy Generates a Convergent Genomic Signature in Mosquitoes and Sandflies |journal=Genome Biology and Evolution |volume=17 |issue=3 |article-number=evaf044 |doi=10.1093/gbe/evaf044 |issn=1759-6653 |pmc=11925016 |pmid=40066743}}</ref> About 14,000 species of arthropods are hematophagous,<ref>{{Cite journal |last1=Fontaine |first1=Albin |last2=Diouf |first2=Ibrahima |last3=Bakkali |first3=Nawal |last4=Missé |first4=Dorothée |last5=Pagès |first5=Frédéric |last6=Fusai |first6=Thierry |last7=Rogier |first7=Christophe |last8=Almeras |first8=Lionel |date=2011-09-28 |title=Implication of haematophagous arthropod salivary proteins in host-vector interactions |journal=Parasites & Vectors |volume=4 |article-number=187 |doi=10.1186/1756-3305-4-187 |doi-access=free |issn=1756-3305 |pmc=3197560 |pmid=21951834}}</ref> even including some genera that were not previously thought to be, such as moths of the genus ''Calyptra''. Hematophagy in insects, including mosquitoes, is thought to have arisen from phytophagous or entomophagous origins.<ref>{{Cite book|title=The biology of blood-sucking in insects| vauthors = Lehane MJ |date=2005|publisher=Cambridge University Press|isbn=0-511-11553-9|edition=2nd|location=Cambridge|oclc=61354292}}</ref><ref>{{Cite journal| vauthors = Mattingly PF |date=1965| veditors = Taylor AE |title=The evolution of parasite-arthropod vector systems|url=https://www.cabdirect.org/cabdirect/abstract/19650802855|journal=Evolution of Parasites. Symposium of the British Society for Parasitology (3rd), London, November 6, 1964|publisher=Oxford: Blackwell Scientific Publications.|pages=29–45}}</ref><ref>{{cite journal | vauthors = Peach DA, Gries R, Zhai H, Young N, Gries G | title = Multimodal floral cues guide mosquitoes to tansy inflorescences | journal = Scientific Reports | volume = 9 | issue = 1 | article-number = 3908 | date = March 2019 | pmid = 30846726 | pmc = 6405845 | doi = 10.1038/s41598-019-39748-4 | bibcode = 2019NatSR...9.3908P }}</ref><ref>{{cite journal|last1=Peach|first1=Daniel A. H.|last2=Gries|first2=Gerhard | name-list-style = vanc |date=2019|title=Mosquito phytophagy – sources exploited, ecological function, and evolutionary transition to haematophagy |journal=Entomologia Experimentalis et Applicata |volume=168|issue=2|pages=120–136|doi=10.1111/eea.12852|issn=1570-7458 |doi-access=free}}</ref> Several complementary biological adaptations for locating the hosts (usually in the dark, as most hematophagous species are nocturnal and silent to avoid detection) have also evolved, such as special physical or chemical detectors for sweat components, CO<sub>2</sub>, heat, light, movement, etc.

In addition to these biological adaptations that have evolved to help blood-feeding arthropods locate hosts, there is evidence that RNA from host species may also be taken up and have regulatory consequences in blood feeding insects. A study on the yellow fever mosquito ''Aedes aegypti'' has shown that human blood microRNA has-miR-21 are taken up during blood feeding and transported into the fat body tissues. Once in the fat body they target and regulate mosquito genes such as vitellogenin, which is a yolk protein used for egg production.<ref name="pmid34244602">{{cite journal| display-authors=6| title=Human blood microRNA hsa-miR-21-5p induces vitellogenin in the mosquito Aedes aegypti. | journal=Commun Biol | year= 2021 | volume= 4 | issue= 1 | page= 856 | pmid=34244602 | doi=10.1038/s42003-021-02385-7 | pmc=8270986 | last1=Perdomo | first1=Hugo D. | last2=Hussain | first2=Mazhar | last3=Parry | first3=Rhys | last4=Etebari | first4=Kayvan | last5=Hedges | first5=Lauren M. | last6=Zhang | first6=Guangmei | last7=Schulz | first7=Benjamin L. | last8=Asgari | first8=Sassan }}</ref>

==Medical importance== The phlebotomic action opens a channel for contamination of the host species with bacteria, viruses and blood-borne parasites contained in the hematophagous organism. Thus, many animal and human infectious diseases are transmitted by hematophagous species, such as the bubonic plague,<ref>{{Cite journal |last1=Blakely |first1=Brittny N. |last2=Agnew |first2=John |last3=Gard |first3=Charlotte |last4=Romero |first4=Alvaro |date=2023 |title=Effects of blood meal source on blood consumption and reproductive success of cat fleas, Ctenocephalides felis |journal=PLOS Neglected Tropical Diseases |volume=17 |issue=4 |article-number=e0011233 |doi=10.1371/journal.pntd.0011233 |doi-access=free |issn=1935-2735 |pmc=10101638 |pmid=37053346}}</ref> Chagas disease,<ref name=":0" /> dengue fever, eastern equine encephalitis, filariasis,<ref>{{Citation |last=Goldin |first=Jennifer |title=Filariasis |date=2026 |work=StatPearls |url=http://www.ncbi.nlm.nih.gov/books/NBK556012/ |access-date=2026-05-15 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=32310472 |last2=Juergens |first2=Andrew L.}}</ref> leishmaniasis, Lyme disease, malaria, rabies,<ref>{{Cite journal |last1=Johnson |first1=Nicholas |last2=Aréchiga-Ceballos |first2=Nidia |last3=Aguilar-Setien |first3=Alvaro |date=2014-04-29 |title=Vampire bat rabies: ecology, epidemiology and control |journal=Viruses |volume=6 |issue=5 |pages=1911–1928 |doi=10.3390/v6051911 |doi-access=free |issn=1999-4915 |pmc=4036541 |pmid=24784570}}</ref> sleeping sickness,<ref>{{Cite journal |last1=Wamwiri |first1=Florence Njeri |last2=Changasi |first2=Robert Emojong |date=2016 |title=Tsetse Flies (Glossina) as Vectors of Human African Trypanosomiasis: A Review |journal=BioMed Research International |volume=2016 |article-number=6201350 |doi=10.1155/2016/6201350 |doi-access=free |issn=2314-6141 |pmc=4789378 |pmid=27034944}}</ref> St. Louis encephalitis, tularemia,<ref>{{Cite news |date=2024-06-12 |title=About Tularemia |url=https://www.cdc.gov/tularemia/about/index.html |archive-url=https://web.archive.org/web/20240823122706/https://www.cdc.gov/tularemia/about/index.html |archive-date=2024-08-23 |access-date=2026-05-15 |work=Tularemia |language=en-us}}</ref> typhus, Rocky Mountain spotted fever, West Nile fever, Zika fever, and many others.{{Citation needed|date=April 2026}}

Insects and arachnids of medical importance for being hematophagous, at least in some species, include the sandfly, blackfly, tsetse fly, bedbug, assassin bug, mosquito, tick, louse, mite, midge, and flea.

Many blood-feeding insects and arachnids, including mosquitoes,<ref>{{Cite journal |last1=Haines |first1=Lee R. |last2=Trett |first2=Anna |last3=Rose |first3=Clair |last4=García |first4=Natalia |last5=Sterkel |first5=Marcos |last6=McGuinness |first6=Dagmara |last7=Regnault |first7=Clément |last8=Barrett |first8=Michael P. |last9=Leroy |first9=Didier |last10=Burrows |first10=Jeremy N. |last11=Biagini |first11=Giancarlo |last12=Ranganath |first12=Lakshminarayan R. |last13=Aljayyoussi |first13=Ghaith |last14=Acosta-Serrano |first14=Álvaro |date=2025-03-26 |title=Anopheles mosquito survival and pharmacokinetic modeling show the mosquitocidal activity of nitisinone |url=https://www.science.org/doi/10.1126/scitranslmed.adr4827 |journal=Science Translational Medicine |volume=17 |issue=791 |article-number=eadr4827 |doi=10.1126/scitranslmed.adr4827|pmid=40138457 |url-access=subscription }}</ref><ref>{{Cite journal |last1=Stavrou-Dowd |first1=Zachary Thomas |last2=Parsons |first2=George |last3=Rose |first3=Clair |last4=Brown |first4=Faye |last5=Lees |first5=Rosemary Susan |last6=Acosta-Serrano |first6=Álvaro |last7=Haines |first7=Lee Rafuse |date=2025-07-31 |title=The β-triketone, nitisinone, kills insecticide-resistant mosquitoes through cuticular uptake |journal=Parasites & Vectors |volume=18 |issue=1 |page=316 |doi=10.1186/s13071-025-06939-0 |doi-access=free |issn=1756-3305 |pmc=12315382 |pmid=40745331}}</ref> tsetse flies,<ref>{{Cite journal |last1=Sterkel |first1=Marcos |last2=Haines |first2=Lee R. |last3=Casas-Sánchez |first3=Aitor |last4=Adung'a |first4=Vincent Owino |last5=Vionette-Amaral |first5=Raquel J. |last6=Quek |first6=Shannon |last7=Rose |first7=Clair |last8=Santos |first8=Mariana Silva dos |last9=Escude |first9=Natalia García |last10=Ismail |first10=Hanafy M. |last11=Paine |first11=Mark I. |last12=Barribeau |first12=Seth M. |last13=Wagstaff |first13=Simon |last14=MacRae |first14=James I. |last15=Masiga |first15=Daniel |date=2021-01-26 |title=Repurposing the orphan drug nitisinone to control the transmission of African trypanosomiasis |journal=PLOS Biology |language=en |volume=19 |issue=1 |article-number=e3000796 |doi=10.1371/journal.pbio.3000796 |doi-access=free |issn=1545-7885 |pmc=7837477 |pmid=33497373}}</ref> kissing bugs,<ref>{{Cite journal |last1=Sterkel |first1=Marcos |last2=Perdomo |first2=Hugo D. |last3=Guizzo |first3=Melina G. |last4=Barletta |first4=Ana Beatriz F. |last5=Nunes |first5=Rodrigo D. |last6=Dias |first6=Felipe A. |last7=Sorgine |first7=Marcos H. F. |last8=Oliveira |first8=Pedro L. |date=2016-08-22 |title=Tyrosine Detoxification Is an Essential Trait in the Life History of Blood-Feeding Arthropods |url=https://www.sciencedirect.com/science/article/pii/S0960982216306649 |journal=Current Biology |volume=26 |issue=16 |pages=2188–2193 |doi=10.1016/j.cub.2016.06.025 |pmid=27476595 |bibcode=2016CBio...26.2188S |issn=0960-9822|url-access=subscription }}</ref> bed bugs,<ref>{{Cite journal |last1=Sterkel |first1=Marcos |last2=Tompkin |first2=Joshua |last3=Schal |first3=Coby |last4=Guerra |first4=Luiza R. M. |last5=Pessoa |first5=Grasielle C. D. |last6=Oliveira |first6=Pedro L. |last7=Benoit |first7=Joshua B. |date=2025 |title=Deployment and transcriptional evaluation of nitisinone, an FDA-approved drug, to control bed bugs |journal=Pest Management Science |language=en |volume=81 |issue=4 |pages=2155–2164 |doi=10.1002/ps.8614 |issn=1526-4998 |pmc=11908903 |pmid=39865399 |bibcode=2025PMSci..81.2155S }}</ref> and ticks,<ref>{{Cite journal |last1=McComic |first1=Sarah E. |last2=Duke |first2=Stephen O. |last3=Burgess |first3=Edwin R. |last4=Swale |first4=Daniel R. |date=2023-08-01 |title=Defining the toxicological profile of 4-hydroxyphenylpyruvate dioxygenase-directed herbicides to Aedes aegypti and Amblyomma americanum |url=https://www.sciencedirect.com/science/article/pii/S0048357523001979 |journal=Pesticide Biochemistry and Physiology |volume=194 |article-number=105532 |doi=10.1016/j.pestbp.2023.105532 |pmid=37532340 |bibcode=2023PBioP.19405532M |issn=0048-3575|url-access=subscription }}</ref> rely on 4-hydroxyphenylpyruvate dioxygenase (HPPD) to degrade excess tyrosine after a bloodmeal. Inhibiting HPPD with compounds such as nitisinone causes lethal tyrosine accumulation, killing vectors after feeding and, in mosquitoes, even after brief contact with treated surfaces.<ref>{{Cite journal |last1=Stavrou-Dowd |first1=Zachary Thomas |last2=Parsons |first2=George |last3=Rose |first3=Clair |last4=Brown |first4=Faye |last5=Lees |first5=Rosemary Susan |last6=Acosta-Serrano |first6=Álvaro |last7=Haines |first7=Lee Rafuse |date=2025-07-31 |title=The β-triketone, nitisinone, kills insecticide-resistant mosquitoes through cuticular uptake |journal=Parasites & Vectors |volume=18 |issue=1 |page=316 |doi=10.1186/s13071-025-06939-0 |doi-access=free |issn=1756-3305 |pmc=12315382 |pmid=40745331}}</ref> This distinct metabolic vulnerability offers a potential route for broad-spectrum vector control beyond conventional neurotoxic insecticides.

Hematophagous organisms have been used by physicians for beneficial purposes (hirudotherapy). Some doctors now use leeches to prevent the clotting of blood on some wounds following surgery or trauma.<ref>{{Cite journal |last1=Abdualkader |first1=A. M. |last2=Ghawi |first2=A. M. |last3=Alaama |first3=M. |last4=Awang |first4=M. |last5=Merzouk |first5=A. |date=2013 |title=Leech therapeutic applications |journal=Indian Journal of Pharmaceutical Sciences |volume=75 |issue=2 |pages=127–137 |issn=0250-474X |pmc=3757849 |pmid=24019559}}</ref> The anticoagulants in the laboratory-raised leeches' saliva keeps fresh blood flowing to the site of an injury, actually preventing infection and increasing chances of full recovery. In a recent study a genetically engineered drug called desmoteplase based on the saliva of ''Desmodus rotundus'' (a vampire bat) was shown to improve recovery in stroke patients.<ref>{{Cite journal |doi=10.1161/01.STR.0000217403.66996.6d |pmid=16574922 |title=Dose Escalation of Desmoteplase for Acute Ischemic Stroke (DEDAS) |year=2006 |last1=Furlan |first1=Anthony J. |last2=Eyding |first2=Dirk |last3=Albers |first3=Gregory W. |last4=Al-Rawi |first4=Yasir |last5=Lees |first5=Kennedy R. |last6=Rowley |first6=Howard A. |last7=Sachara |first7=Christian |last8=Soehngen |first8=Mariola |last9=Warach |first9=Steven |last10=Hacke |first10=Werner |author11=DEDAS Investigators |journal=Stroke |volume=37 |issue=5 |pages=1227–1231 |s2cid=2547258 |doi-access=free }}</ref>

==Human hematophagy== {{main|Blood as food|Clinical vampirism}} {{see also|Food and drink prohibitions#Blood}} Many human societies also drink blood or use it to manufacture foodstuffs and delicacies. Cow blood mixed with milk, for example, is a mainstay food of the African Maasai.<ref>{{Cite magazine |last=Bhatia |first=Aatish |title=Milk, meat and blood: how diet drives natural selection in the Maasai |url=https://www.wired.com/2012/09/milk-meat-and-blood-how-diet-drives-natural-selection-in-the-maasai/ |access-date=2026-04-25 |magazine=Wired |language=en-US |issn=1059-1028}}</ref> Many places around the world eat blood sausage.<ref>{{Cite journal |last=Ku |first=Su-Kyung |last2=Kim |first2=Jake |last3=Kim |first3=Yea-Ji |last4=Choi |first4=Yun-Sang |date=2025 |title=Digestibility and Physicochemical Characteristics of Blood Sausages Made with Korean Traditional Fermented Food |url=https://pubmed.ncbi.nlm.nih.gov/41821699 |journal=Food Science of Animal Resources |volume=45 |issue=5 |pages=1280–1292 |doi=10.5851/kosfa.2024.e86 |issn=2636-0780 |pmc=12965254 |pmid=41821699}}</ref> Some societies, such as the Moche,{{Citation needed|date=April 2026}} had ritual hematophagy, as well as the Scythians,<ref>{{Cite web |last=McCann |first=Shaun Richard |date=2021-08-16 |title=How Our Attitude to Blood Has Changed Over the Millennia • The Blood Project |url=https://www.thebloodproject.com/how-our-attitude-to-blood-has-changed-over-the-millennia/ |access-date=2026-04-25 |website=The Blood Project}}</ref> a nomadic people of Eastern Europe, who drank the blood of the first enemy they killed in battle.{{Citation needed|date=April 2026}} Psychiatric cases of patients performing hematophagy also exist. Sucking or licking one's own blood from a wound<ref>{{Cite web |date=2015-09-29 |title=Why do people instinctively suck on a bleeding wound? |url=https://www.thenakedscientists.com/articles/questions/why-do-people-instinctively-suck-bleeding-wound |access-date=2025-06-21 |website=www.thenakedscientists.com |language=en-gb}}</ref> to clean it is also a common human behavior, and in small enough quantities is not considered taboo. Finally, human vampirism has been a persistent object of literary and cultural attention.<ref>{{Cite web |date=2025-06-21 |title=How popular culture changed our view of the vampire |url=https://www.nationalgeographic.com/history/article/how-popular-culture-changed-our-view-of-the-vampire |access-date=2025-06-21 |website=History |language=en}}</ref>

== References == {{Reflist}}

== Further reading == {{refbegin}} * {{cite journal |vauthors=Scharfetter C, Hagenbuchner K |title=Blutdurst als Symptom. Ein seltsamer Fall von Bluttrinken |journal=Psychiatr Neurol |volume=154 |issue=5 |pages=288–310 |year=1967 |location=Basel |doi=10.1159/000126021 }} * {{cite journal |vauthors=Ciprandi A, Horn F, Termignoni C |title=Saliva of hematophagous animals: source of new anticoagulants |journal=Rev. Bras. Hematol. Hemoter. |volume=25 |issue=4 |pages=250–262 |year=2003 |url=http://www.scielo.br/scielo.php?pid=S1516-84842003000400012&script=sci_pdf&tlng=pt |format=PDF}} * {{cite journal | vauthors = Markwardt F | title = Hirudin as alternative anticoagulant--a historical review | journal = Seminars in Thrombosis and Hemostasis | volume = 28 | issue = 5 | pages = 405–14 | date = October 2002 | pmid = 12420235 | doi = 10.1055/s-2002-35292 | s2cid = 23103375 }} * {{cite journal | vauthors = Ribeiro JM | title = Blood-feeding arthropods: live syringes or invertebrate pharmacologists? | journal = Infectious Agents and Disease | volume = 4 | issue = 3 | pages = 143–52 | date = September 1995 | pmid = 8548192 }} {{refend}}

Category:Haematophagy Category:Carnivory