Vampire bat

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Vampire bat
Desmodus rotundus A Catenazzi.jpg
Common vampire bat (Desmodus rotundus)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Chiroptera
Family: Phyllostomidae
Subfamily: Desmodontinae
Bonaparte, 1845
Genera

Vampire bats, members of the subfamily Desmodontinae, are leaf-nosed bats currently found in Central and South America. Their food source is the blood of other animals, a dietary trait called hematophagy. Three extant bat species feed solely on blood: the common vampire bat (Desmodus rotundus), the hairy-legged vampire bat (Diphylla ecaudata), and the white-winged vampire bat (Diaemus youngi). Two extinct species of the genus Desmodus have been found in North America.

Contents

Taxonomy

Due to differences among the three species, each has been placed within a different genus, each consisting of one extant species. In the older literature, these three genera were placed within a family of their own, Desmodontidae, but taxonomists have now grouped them as a subfamily, Desmodontinae, in the New World leaf-nosed bat family, Phyllostomidae. [1]

The three known species of vampire bats all seem more similar to one another than to any other species. That suggests that hematophagy evolved only once, and the three species share this common ancestor. [1] : 163–167 

The placement of the three genera of the subfamily Desmodontinae within the New World leaf-nosed bat family Phyllostomidae Gray, 1825, may be summarized as: [2]

Evolution

Vampire bats are in a diverse family of bats that consume many food sources, including nectar, pollen, insects, fruit and meat. [1] The three species of vampire bats are the only mammals that have evolved to feed exclusively on blood (hematophagy) as micropredators, a strategy within parasitism. [4] [5] Hematophagy is uncommon due to the number of challenges to overcome for success: a large volume of liquid potentially overwhelming the kidneys and bladder, [6] the risk of iron poisoning, [7] and coping with excess protein. [8] There are multiple hypotheses for how vampire bats evolved.

The vampire bat lineage diverged from its family 26 million years ago. [15] The hairy-legged vampire bat likely diverged from the other two species of vampire bats 21.7 million years ago. [15] Because the hairy-legged vampire bat feeds on bird blood and it is the most basal of living vampire bats, it is considered likely that the first vampire bats fed on bird blood as well. [15] Recent analyses suggest that vampire bats arose from insectivores, which discount the frugivore, carnivore, and nectarivore hypotheses of origin. [15] Within 4 million years of diverging from other Phyllostomidae, vampire bats had evolved all necessary adaptations for blood-feeding, making it one of the fastest examples of natural selection among mammals. [15]

Anatomy and physiology

A vampire bat skeleton, showing the distinctive incisors and canines Vampire bat skeleton face.jpg
A vampire bat skeleton, showing the distinctive incisors and canines

Unlike fruit bats, the vampire bats have short, conical muzzles. They also lack a nose leaf, instead having naked pads with U-shaped grooves at the tip. The common vampire bat, Desmodus rotundus, also has specialized thermoreceptors on its nose, [16] which aid the animal in locating areas where the blood flows close to the skin of its prey. A nucleus has been found in the brain of vampire bats that has a similar position and similar histology to the infrared receptor of infrared-sensing snakes. [17] [18]

A vampire bat has front teeth that are specialized for cutting and the back teeth are much smaller than in other bats. The inferior colliculus, the part of the bat's brain that processes sound, is well adapted to detecting the regular breathing sounds of sleeping animals that serve as its main food source. [19] [20]

While other bats have almost lost the ability to maneuver on land, vampire bats can walk, jump, and even run by using a unique, bounding gait, in which the forelimbs instead of the hindlimbs are recruited for force production, as the wings are much more powerful than the legs. This ability to run seems to have evolved independently within the bat lineage. [21]

Vampire bats also have a high level of resistance to a group of bloodborne viruses known as endogenous retroviruses, which insert copies of their genetic material into their host's genome. [22]

It was recently discovered that the vampire bat's loss of the REP15 gene allows for enhanced iron secretion in adaptation to the high iron diet. [23]

Vampire bats use infrared radiation to locate blood hotspots on their prey. A recent study has shown that common vampire bats tune a TRP-channel that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C (86 °F). This is achieved through alternative splicing of TRPV1 transcripts to produce a channel with a truncated carboxy-terminal cytoplasmic domain. These splicing events occur exclusively in trigeminal ganglia, and not in dorsal root ganglia, thereby maintaining a role for TRPV1 as a detector of noxious heat in somatic afferents. [24] The only other known vertebrates capable of detecting infrared radiation are boas, pythons and pit vipers, all of which have pit organs.

Ecology and life cycle

Vampire bats tend to live in colonies in almost completely dark places, such as caves, old wells, hollow trees, and buildings. They range in Central to South America and live in arid to humid, tropical and subtropical areas. Vampire bat colony numbers can range from single digits to hundreds in roosting sites. The basic social structure of roosting bats is made of female groups and their offspring, a few adult males, known as "resident males", and a separate group of males, known as "nonresident males". [25] In hairy-legged vampire bats, the hierarchical segregation of nonresident males appears less strict than in common vampire bats. [26] Nonresident males are accepted into the harems when the ambient temperature lowers. This behavior suggests social thermoregulation.

Resident males mate with the females in their harems, and it is less common for outside males to copulate with the females. [25] Female offspring often remain in their natal groups. [25] Several matrilines can be found in a group, as unrelated females regularly join groups. [25] Male offspring tend to live in their natal groups until they are about two years old, sometimes being forcibly expelled by the resident adult males. [25] Vampire bats on average live about nine years when they are in their natural environment in the wild. [27]

Vampire bats form strong bonds with other members of the colony. A related unique adaptation of vampire bats is the sharing of food. A vampire bat can only survive about two days without feeding, yet they cannot be guaranteed of finding food every night. This poses a problem, so when a bat fails to find food, it will often "beg" another bat for food. A "donor" bat may regurgitate a small amount of blood to sustain the other member of the colony. For equally familiar bats, the predictive capacity of reciprocity surpasses that of relatedness. [28] This finding suggests that vampire bats are capable of preferentially aiding their relatives, but that they may benefit more from forming reciprocal, cooperative relationships with relatives and non-relatives alike. [28] Furthermore, donor bats were more likely to approach starving bats and initiate the food sharing. When individuals of a population are lost, bats with a larger number of mutual donors tend to offset their own energetic costs at a higher rate than bats that fed less of the colony before the removal. Individuals that spend their own energy as a social investment of sorts are more likely to thrive, and higher rates of survival incentivize the behavior and reinforce the importance of large social networks in colonies. [29] These findings contradict the harassment hypothesis—which claims that individuals share food in order to limit harassment by begging individuals. [28] All considered, vampire bat research should be interpreted cautiously as much of the evidence is correlational and still requires further testing. [30]

Another ability that some vampire bats possess is identifying and monitoring the positions of conspecifics (individuals of the same species) simply by antiphonal calling. [31] Similar in nature to the sound mother bats make to call to their pups, these calls tend to vary on a bat to bat basis which may help other bats identify individuals both in and outside of their roost. [32]

Vampire bats also engage in social grooming. [33] It usually occurs between females and their offspring, but it is also significant between adult females. Social grooming is mostly associated with food sharing. [33]

Feeding

A vampire bat feeding on a pig (taxidermy specimens) Desmodus rotundus feeding.jpg
A vampire bat feeding on a pig (taxidermy specimens)

Vampire bats hunt only when it is fully dark. Like fruit-eating bats, and unlike insectivorous and fish-eating bats, they emit only low-energy sound pulses. The common vampire bat feeds primarily on the blood of mammals (occasionally including humans), whereas both the hairy-legged vampire bat and white-winged vampire bat feed primarily on the blood of birds. Once the common vampire bat locates a host, such as a sleeping mammal, it lands and approaches it on the ground while on all fours. It then likely uses thermoception to identify a warm spot on the skin to bite. They then create a small incision with their teeth and lap up blood from the wound.

Vampire bats, like snakes, have developed highly sensitive thermosensation, with specialized systems for detecting infrared radiation. Snakes co-opt a non-heat-sensitive channel, vertebrate TRPA1 (transient receptor potential cation channel A1), to produce an infrared detector. However, vampire bats tune a channel that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C (86 °F), which allows them to sense the target. [34]

As noted by Arthur M. Greenhall:

The most common species, the common vampire (Desmodus) is not fastidious and will attack any warm-blooded animal. The white-winged vampire (Diaemus) appears to have a special preference for birds and goats. In the laboratory it has not been possible to feed Diaemus on cattle blood. [35]

If there is fur on the skin of the host, the common vampire bat uses its canine and cheek teeth like a barber's blades to shave away the hairs. The bat's razor-sharp upper incisor teeth then make a 7 mm wide and 8 mm deep cut. The upper incisors lack enamel, which keeps them permanently razor sharp. [36] Their teeth are so sharp, even handling their skulls in a museum can result in cuts. [37]

The bat's saliva, left in the victim's resulting bite wound, has a key function in feeding from the wound. The saliva contains several compounds that prolong bleeding, such as anticoagulants that inhibit blood clotting, [38] and compounds that prevent the constriction of blood vessels near the wound.

Digestion

A typical female vampire bat weighs 40 grams (1.4 oz) and can consume over 20 grams (1 fluid ounce) of blood in a 20-minute feed. This feeding behavior is facilitated by its anatomy and physiology for rapid processing and digestion of the blood to enable the animal to take flight soon after the feeding. The stomach and intestine rapidly absorb the water in the blood meal, which is quickly transported to the kidneys, and on to the bladder for excretion. [39] [40] A common vampire bat begins to expel urine within two minutes of feeding. While shedding much of the blood's liquid facilitates flight takeoff, the bat still has added almost 20–30% of its body weight in blood. To take off from the ground, the bat generates extra lift by crouching and flinging itself into the air. [41] Typically, within two hours of setting out in search of food, the common vampire bat returns to its roost and settles down to spend the rest of the night digesting its meal. Digestion is aided by their microbiome, and their genome protects them against pathogens in the blood. [42] Its stool is roughly the same as that from bats eating fruits or insects. [43]

Human health

Common vampire bat at the Louisville Zoo Vampire Bat 12.jpg
Common vampire bat at the Louisville Zoo

Rabies

Rabies can be transmitted to humans and other animals by vampire bat bites. Since dogs are now widely immunized against rabies, the number of human rabies transmissions by vampire bats exceeds those by dogs in Latin America, with 55 documented cases in 2005. [44] The risk of infection to the human population is less than to livestock exposed to bat bites. [45] Various estimates of the prevalence of rabies in bat populations have been made; it has been estimated that less than 1% of wild bats in regions where rabies is endemic are infected with the virus at any given time. [46] Bats that are infected may be clumsy, disoriented, and unable to fly. [47]

Anticoagulant drug

The unique properties of vampire bat saliva have found some positive use in medicine.

Various studies published in Stroke: Journal of the American Heart Association on a genetically engineered drug called desmoteplase which uses the anticoagulant properties of the saliva of Desmodus rotundus found that it increased blood flow in stroke patients. [48]

See also

Footnotes

  1. 1 2 3 Wetterer, Andrea L.; Rockman, Matthew V.; Simmons, Nancy B. (2000). "Phylogeny of phyllostomid bats (Mammalia: Chiroptera): data from diverse morphological systems, sex chromosomes, and restriction sites" (PDF). Bull. Am. Mus. Nat. Hist. 248: 1–200. doi:10.1206/0003-0090(2000)248<0001:popbmc>2.0.co;2. hdl:2246/1595. S2CID   83617355. Archived from the original (PDF) on 2014-02-03. Retrieved 2013-02-22.
  2. ↑ Simmons, N.B. (2005). "Order Chiroptera". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 312–529. ISBN   978-0-8018-8221-0. OCLC   62265494.
  3. ↑ "Fossilworks: Desmodus". fossilworks.org. Retrieved 17 December 2021.
  4. ↑ Botero-Castro, Fidel; Tilak, Marie-Ka; Justy, Fabienne; Catzeflis, Francois; Delsuc, Frédéric; Douzery, Emmanuel J.P. (2018). "In cold blood: Compositional Bias and Positive Selection Drive the High Evolutionary Rate of Vampire Bats Mitochondrial Genomes". Genome Biology and Evolution. 10 (9): 2218–2239. doi:10.1093/gbe/evy120. PMC   6127110 . PMID   29931241.
  5. ↑ Poulin, Robert; Randhawa, Haseeb S. (February 2015). "Evolution of parasitism along convergent lines: from ecology to genomics". Parasitology. 142 (Suppl 1): S6–S15. doi:10.1017/S0031182013001674. PMC   4413784 . PMID   24229807.
  6. ↑ Breidenstein C. P. (1982). "Digestion and assimilation of bovine blood by a vampire bat (Desmodus rotundus)". Journal of Mammalogy. 63 (3): 482–484. doi:10.2307/1380446. JSTOR   1380446.
  7. ↑ Morton D.; Wimsatt W. A. (1980). "Distribution of iron in the gastrointestinal tract of the common vampire bat: Evidence for macrophage‐linked iron clearance". The Anatomical Record. 198 (2): 183–192. doi:10.1002/ar.1091980206. PMID   7212303. S2CID   13463459.
  8. ↑ Singer M. A. (2002). "Vampire bat, shrew, and bear: comparative physiology and chronic renal failure". American Journal of Physiology. Regulatory, Integrative and Comparative Physiology. 282 (6): R1583–R1592. doi:10.1152/ajpregu.00711.2001. PMID   12010738.
  9. ↑ Slaughter, B. H. (1970). "Evolutionary trends of chiropteran dentitions". About Bats. Dallas: Southern Methodist University Press. pp. 51–83.
  10. ↑ Gillette, D. D. (1975). "Evolution of feeding strategies in bats". Tebiwa. 18: 39–48.
  11. ↑ Fenton M. B. (1992). "Wounds and the origin of blood‐feeding in bats". Biological Journal of the Linnean Society. 47 (2): 161–171. doi:10.1111/j.1095-8312.1992.tb00662.x.
  12. ↑ Sazima I (1978). "Vertebrates as food items of the woolly false vampire, Chrotopterus auritus". Journal of Mammalogy. 59 (3): 617–618. doi:10.2307/1380238. JSTOR   1380238.
  13. ↑ Schutt, W. A., Jr. (1998). "Chiropteran hindlimb morphology and the origin of blood-feeding in bats". In T. H. Kunz, and P. A. Racey (eds.), Bat biology and conservation. Washington D.C.: Smithsonian Inst. pp. 157–168. ISBN   978-1560988250
  14. ↑ Baker, Robert J.; Carter, Dilford C.; Jones, J. Knox. (1976). Biology of bats of the New World family Phyllostomatidae /. doi: 10.5962/bhl.title.142603 .
  15. 1 2 3 4 5 Baker, R. J.; Bininda-Emonds, O. R.; Mantilla-Meluk, H.; Porter, C. A.; Van Den Bussche, R. A. (2012). "Molecular timescale of diversification of feeding strategy and morphology in New World leaf-nosed bats (Phyllostomidae): a phylogenetic perspective". In Gunnell, Gregg F; Simmons, Nancy B (eds.). Evolutionary history of bats: fossils, molecules and morphology. pp. 385–409. doi:10.1017/CBO9781139045599.012. ISBN   9781139045599.
  16. ↑ Kürten, Ludwig; Schmidt, Uwe; Schäfer, Klaus (1984). "Warm and Cold Receptors in the Nose of the Vampire Bat Desmodus rotundus". Naturwissenschaften. 71 (6): 327–328. Bibcode:1984NW.....71..327K. doi:10.1007/BF00396621. PMID   6472483. S2CID   31899356.
  17. ↑ Campbell, Angela L.; Naik, Rajesh R.; Sowards, Laura; Stone, Morley O. (2002). "Biological infrared imaging and sensing" (PDF). Micron. 33 (2): 211–225. doi:10.1016/S0968-4328(01)00010-5. PMID   11567889. Archived from the original (PDF) on 2003-06-15.
  18. ↑ Kishida R, Goris RC, Terashima S, Dubbeldam J (1984). "A suspected infrared-recipient nucleus in the brainstem of the vampire bat, Desmodus rotundus". Brain Res. 322 (2): 351–355. doi:10.1016/0006-8993(84)90132-X. PMID   6509324. S2CID   33339192.
  19. ↑ Schmidt, U.; Schlegel, P.; Schweizer, H.; Neuweiler, G. (1991). "Audition in vampire bats, Desmodus rotundus" (PDF). J Comp Physiol. 168: 45–51. CiteSeerX   10.1.1.652.9590 . doi:10.1007/bf00217102. S2CID   15533612.
  20. ↑ Gröger, Udo & Wiegrebe, Lutz (2006). "Classification of human breathing sounds by the common vampire bat, Desmodus rotundus". BMC Biology. 4: 18. doi: 10.1186/1741-7007-4-18 . PMC   1513255 . PMID   16780579.
  21. ↑ Riskin, Daniel K.; Hermanson, John W. (2005). "Independent evolution of running in vampire bats". Nature. 434 (7031): 292. doi: 10.1038/434292a . PMID   15772640. S2CID   4406312.
  22. ↑ Arnold, Carrie (22 February 2018). "Vampire Bats Survive by Only Eating Blood—Now We Know How". National Geographic. Archived from the original on 18 September 2021.
  23. ↑ Moritz Blumer et al. ,Gene losses in the common vampire bat illuminate molecular adaptations to blood feeding.Sci. Adv.8,eabm6494(2022).DOI:10.1126/sciadv.abm6494
  24. ↑ Gracheva, Elena O.; Cordero-Morales, Julio F.; González-Carcacía, José A.; Ingolia, Nicholas T.; Manno, Carlo; Aranguren, Carla I.; Weissman, Jonathan S.; Julius, David (2011). "Ganglion-specific splicing of TRPV1 underlies infrared sensation in vampire bats". Nature. 476 (7358): 88–91. doi:10.1038/nature10245. PMC   3535012 . PMID   21814281.
  25. 1 2 3 4 5 Wilkinson G. S. (1985). "The Social Organization of the Common Vampire Bat II:Mating System, Genetic Structure and Relatedness". Behavioral Ecology and Sociobiology. 17 (2): 123–134. doi:10.1007/BF00299244. JSTOR   4599815. S2CID   12460893.
  26. ↑ Delpietro H. A., Russo R. G. (2002). "Observations of the common vampire bat (Desmodus rotundus) and the hairy-legged vampire bat (Diphylla ecaudata) in captivity". Mammalian Biology – Zeitschrift für Säugetierkunde. 67 (2): 65–78. doi:10.1078/1616-5047-00011.
  27. ↑ "Vampire Bat". Animals. 2014-03-01. Retrieved 2022-12-05.
  28. 1 2 3 Carter, G. G. & Wilkinson, G. S. (2013). "Food sharing in vampire bats: reciprocal help predicts donations more than relatedness or harassment". Proc R Soc B. 280 (1753): 20122573. doi:10.1098/rspb.2012.2573. PMC   3574350 . PMID   23282995.
  29. ↑ Carter, Gerald; Farine, Damien; Wilkinson, Gerald (2017-05-01). "Social bet-hedging in vampire bats". Biology Letters. 13 (5): 20170112. doi:10.1098/rsbl.2017.0112. PMC   5454239 . PMID   28539459.
  30. ↑ Carter, G. & Wilkinson, G. (2013). "Does food sharing in vampire bats demonstrate reciprocity?". Communicative and Integrative Biology. 6 (6): e25783. doi:10.4161/cib.25783. PMC   3913674 . PMID   24505498.
  31. ↑ Carter, G. G.; Fenton, M. B.; Faure, P. A. (2009). "White-winged vampire bats (Diaemus youngi) exchange contact calls". Canadian Journal of Zoology. 87 (7): 604–608. doi:10.1139/Z09-051.
  32. ↑ Carter, Gerald G.; Skowronski, Mark D.; Faure, Paul A.; Fenton, Brock (2008). "Antiphonal calling allows individual discrimination in white-winged vampire bats". Animal Behaviour. 76 (4): 1343–1355. doi:10.1016/j.anbehav.2008.04.023. S2CID   53147832 . Retrieved 2018-12-01.
  33. 1 2 Wilkinson G. S. (1986). "Social grooming in the common vampire bat, Desmodus rotundus". Animal Behaviour. 34 (6): 1880–1889. CiteSeerX   10.1.1.539.5104 . doi:10.1016/s0003-3472(86)80274-3. S2CID   11214563.
  34. ↑ Gracheva, Elena (August 4, 2011). "Ganglion-specific splicing of TRPV1 underlies infrared sensation in vampire bats". Nature. 476 (7358): 88–91. doi:10.1038/nature10245. PMC   3535012 . PMID   21814281.
  35. ↑ Greenhall, Arthur M. (1961). Bats in Agriculture, p. 8. A Ministry of Agriculture Publication. Trinidad and Tobago.
  36. ↑ Greenhall, Arthur M. (1988) "Feeding Behavior". In: Natural History of Vampire Bats (ed. by A. M. Greenhall and U. Schmidt), pp. 111–132. Boca Raton, FL: CRC Press. ISBN   978-0-8493-6750-2
  37. ↑ Callaway, Ewen (October 31, 2008). "How vampires evolved to live on blood alone". New Scientist. Reed Business Information Ltd. "You can actually cut yourself handling a bat skull in a museum, they're that sharp"
  38. ↑ Hawkey, Christine (1966). "Plasminogen Activator in Saliva of the Vampire Bat Desmodus rotundus". Nature. 211 (5047): 434–435. Bibcode:1966Natur.211..434H. doi:10.1038/211434c0. PMID   5967844. S2CID   5301723.
  39. ↑ Price E. R.; Brun A.; Gontero-Fourcade M.; Fernández-Marinone G.; Cruz-Neto A. P.; Karasov W. H.; Caviedes-Vidal E. (2015). "Intestinal Water Absorption Varies with Expected Dietary Water Load among Bats but Does Not Drive Paracellular Nutrient Absorption". Physiol. Biochem. Zool. 88 (6): 680–684. doi:10.1086/683114. hdl: 11336/14629 . PMID   26658415. S2CID   206003403.
  40. ↑ McFarland W. N.; Wimsatt W. A. (1965). "Urine flow and composition in the vampire bat". Am. Zool. 5: 662–667.
  41. ↑ Schutt J. E. A.; Altenbach W. A.; Chang J. S.; Cullinane Y. H.; Hermanson D. M.; Muradali J. W.; Bertram F. (1997). "The dynamics of flight-initiating jumps in the common vampire bat Desmodus rotundus". Journal of Experimental Biology. 200 (23): 3003–3012. doi:10.1242/jeb.200.23.3003. PMID   9359889.
  42. ↑ Katz, Brigit (23 February 2018). "How Vampire Bats Can Survive on a Diet of Blood". Smithsonian . Retrieved 23 February 2018.
  43. ↑ Emerson, Justin K.; Roark, Alison M. (April 2007). "Composition of guano produced by frugivorous, sanguivorous, and insectivorous bats". Acta Chiropterologica. 9 (1): 261–267. doi:10.3161/1733-5329(2007)9[261:COGPBF]2.0.CO;2. S2CID   86038700.
  44. ↑ Schneider, Maria Cristina; Romijn, Phyllis Catharina; Uieda, Wilson; Tamayo, Hugo; Silva, Daniela Fernandes da; Belotto, Albino; Silva, Jarbas Barbosa da; Leanes, Luis Fernando (March 2009). "Rabies transmitted by vampire bats to humans: an emerging zoonotic disease in Latin America?". Revista Panamericana de Salud Pública. 25 (3): 260–269. doi: 10.1590/S1020-49892009000300010 . PMID   19454154.
  45. ↑ "The Art and Science of Bats". Smithsonian Institution.
  46. ↑ Davis, April; Gordy, Paul; Rudd, Robert; Jarvis, Jodie A.; Bowen, Richard A. (2012). "Naturally Acquired Rabies Virus Infections in Wild-Caught Bats". Vector-Borne and Zoonotic Diseases. 12 (1): 55–60. doi: 10.1089/vbz.2011.0674 . ISSN   1530-3667. PMC   3249890 . PMID   21923271.
  47. ↑ "Rabies in bats: how to spot it and report it - Signs that a bat may have rabies". UK Government - Environment. 19 January 2023.
  48. ↑ Hacke, Werner; Albers, Greg; Al-Rawi, Yasir; Bogousslavsky, Julien; Davalos, Antonio; Eliasziw, Michael; Fischer, Michael; Furlan, Anthony; Kaste, Markku; Lees, Kennedy R.; Soehngen, Mariola; Warach, Steven (2005). "The Desmoteplase in Acute Ischemic Stroke Trial (DIAS)". Stroke. 36 (1): 66–73. doi: 10.1161/01.str.0000149938.08731.2c . ISSN   0039-2499. PMID   15569863. A search for "desmoteplase site:ahajournals.org" will find other studies in American Heart Association journals.

Further reading

Related Research Articles

<span class="mw-page-title-main">Microbat</span> Suborder of mammals

Microbats constitute the suborder Microchiroptera within the order Chiroptera (bats). Bats have long been differentiated into Megachiroptera (megabats) and Microchiroptera, based on their size, the use of echolocation by the Microchiroptera and other features; molecular evidence suggests a somewhat different subdivision, as the microbats have been shown to be a paraphyletic group.

In physiology, thermoception or thermoreception is the sensation and perception of temperature, or more accurately, temperature differences inferred from heat flux. It deals with a series of events and processes required for an organism to receive a temperature stimulus, convert it to a molecular signal, and recognize and characterize the signal in order to trigger an appropriate defense response.

<span class="mw-page-title-main">Leaf-nosed bat</span> Family of bats

The New World leaf-nosed bats (Phyllostomidae) are bats found from southern North America to South America, specifically from the Southwest United States to northern Argentina. They are ecologically the most varied and diverse family within the order Chiroptera. Most species are insectivorous, but the phyllostomid bats include within their number true predatory species and frugivores. For example, the spectral bat, the largest bat in the Americas, eats vertebrate prey, including small, dove-sized birds. Members of this family have evolved to use food groups such as fruit, nectar, pollen, insects, frogs, other bats, and small vertebrates, and in the case of the vampire bats, even blood.

<span class="mw-page-title-main">Spectral bat</span> Species of bat

The spectral bat, also called the great false vampire bat, great spectral bat, American false vampire bat or Linnaeus's false vampire bat, is a large, carnivorous leaf-nosed bat found in Mexico, Central America, and South America. It is the only member of the genus Vampyrum; its closest living relative is the big-eared woolly bat. It is the largest bat species in the New World, as well as the largest carnivorous bat: its wingspan is 0.7–1.0 m (2.3–3.3 ft). It has a robust skull and teeth, with which it delivers a powerful bite to kill its prey. Birds are frequent prey items, though it may also consume rodents, insects, and other bats.

<i>Desmodus</i> Genus of bats

Desmodus is a genus of bats which—along with the genera Diaemus and Diphylla—are allied as the subfamily Desmodontinae, the carnivorous, blood-consuming vampire bats of the New World leaf-nosed bat family Phyllostomidae.

<span class="mw-page-title-main">Draculin</span> Glycoprotein found in the saliva of vampire bats

Draculin is a glycoprotein found in the saliva of vampire bats. It is a single-chain polypeptide protein composed of 708 amino acids, weighing about 88.5 kDa when reduced and 83 kDa when non-reduced, and selectively inhibits FIXa and FXa. It functions as an anticoagulant, inhibiting coagulation factors IX (IXa) and X (Xa) by establishing rapid equilibrium with factor Xa, and is the first natural polypeptide which has been described to show immediate anti-IXa and anti-Xa properties. In addition, Draculin inhibits the conversion of prothrombin to thrombin, preventing fibrinogen from converting to fibrin. These two processes inhibit blood coagulation thus keeping the blood of the bitten victim from clotting while the bat is drinking. The activation of factor X is a common point between the intrinsic and extrinsic pathway of blood coagulation. Activated factor X (FXa) is the sole enzyme that catalyzes the conversion of prothrombine into thrombin, which is vital in the coagulation cascade. Draculin is a member of the Lactoferrin family of proteins that functions as an antibacterial protein in other mammals, but has been co-opted in bat evolution to function as an anticoagulant.

<span class="mw-page-title-main">New Zealand lesser short-tailed bat</span> Species of bat

The New Zealand lesser short-tailed bat is a small-sized omnivorous mammal endemic to the islands of New Zealand. It is one of two extant and three overall terrestrial mammal species unique to New Zealand. Its closest relative, the New Zealand greater short-tailed bat, was last seen in 1965 and is presumed extinct due to intense predation from ship rats introduced in the last few centuries. These bats are also commonly referred to as pekapeka, their Māori-language name. Lesser short-tailed bats have unique adaptations that differentiate them from bats found in other parts of the world. For example, they are fully capable of moving along the ground to search for food, and the males sing to attract partners, taking turns to do so. Lesser short-tailed bats are a vulnerable species, so extensive conservation work and research are being done to prevent extinction.

<span class="mw-page-title-main">Surra</span> Parasitic disease of animals

Surra is a disease of vertebrate animals. The disease is caused by protozoan trypanosomes, specifically Trypanosoma evansi, of several species which infect the blood of the vertebrate host, causing fever, weakness, and lethargy which lead to weight loss and anemia. In some animals the disease is fatal unless treated.

<span class="mw-page-title-main">Common vampire bat</span> South and Central American bat

The common vampire bat is a small, leaf-nosed bat native to the Neotropics. It is one of three extant species of vampire bat, the other two being the hairy-legged and the white-winged vampire bats. The common vampire bat practices hematophagy, mainly feeding on the blood of livestock. The bat usually approaches its prey at night while they are sleeping. It then uses its razor-sharp teeth to cut open the skin of its hosts and lap up their blood with its long tongue.

<span class="mw-page-title-main">Hairy-legged vampire bat</span> Species of mammals belonging to the New World leaf-nosed bat family

The hairy-legged vampire bat is one of three extant species of vampire bats. It mainly feeds on the blood of wild birds, but can also feed both on domestic birds and humans. This vampire bat lives mainly in tropical and subtropical forestlands of South America, Central America, and southern Mexico. It is the sole member of the genus Diphylla.

<span class="mw-page-title-main">White-winged vampire bat</span> Species of mammals belonging to the New World leaf-nosed bat family

The white-winged vampire bat, a species of vampire bat, is the only member of the genus Diaemus. They are found from Mexico to northern Argentina and are present on the islands of Trinidad and Margarita.

<span class="mw-page-title-main">Venomous mammal</span> Venom-producing animals of the class Mammalia

Venomous mammals are animals of the class Mammalia that produce venom, which they use to kill or disable prey, to defend themselves from predators or conspecifics or in agonistic encounters. Mammalian venoms form a heterogeneous group with different compositions and modes of action, from three orders of mammals: Eulipotyphla, Monotremata, and Chiroptera. It has been proposed that some members of a fourth order, Primates, are venomous. To explain the rarity of venom delivery in Mammalia, Mark Dufton of the University of Strathclyde has suggested that modern mammalian predators do not need venom because they are able to kill quickly with their teeth or claws, whereas venom, no matter how sophisticated, requires time to disable prey.

The Peuchen is a creature from the Mapuche mythology and Chilote mythology pertaining to southern Chile, a much feared shapeshifting creature that can instantly change into animal form. According to legend, El Peuchen takes the hearts of its victims without leaving a mark on the body.

Desmodus draculae is an extinct species of vampire bat that inhabited Central and South America during the Pleistocene, and possibly the early Holocene. It was 30% larger than its living relative the common vampire bat. Fossils and unmineralized subfossils have been found in Argentina, Mexico, Ecuador, Brazil, Venezuela, Belize, and Bolivia.

<span class="mw-page-title-main">Rabies in animals</span> Deadly zoonotic disease

In animals, rabies is a viral zoonotic neuroinvasive disease which causes inflammation in the brain and is usually fatal. Rabies, caused by the rabies virus, primarily infects mammals. In the laboratory it has been found that birds can be infected, as well as cell cultures from birds, reptiles and insects. The brains of animals with rabies deteriorate. As a result, they tend to behave bizarrely and often aggressively, increasing the chances that they will bite another animal or a person and transmit the disease.

<span class="mw-page-title-main">Bat</span> Order of flying mammals

Bats are flying mammals of the order Chiroptera. With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out digits covered with a thin membrane or patagium. The smallest bat, and arguably the smallest extant mammal, is Kitti's hog-nosed bat, which is 29–34 millimetres in length, 150 mm (6 in) across the wings and 2–2.6 g in mass. The largest bats are the flying foxes, with the giant golden-crowned flying fox reaching a weight of 1.6 kg and having a wingspan of 1.7 m.

<span class="mw-page-title-main">Hematophagy</span> Ecological niche involving feeding on blood

Hematophagy is the practice by certain animals of feeding on blood. 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 are hematophagous. The spider Evarcha culicivora feeds indirectly on vertebrate blood by specializing on blood-filled female mosquitoes as their preferred prey. Some fish, such as lampreys and candirus; mammals, especially vampire bats; and birds, including the vampire finch, Hood mockingbird, Tristan thrush, and oxpeckers, also practise hematophagy.

<span class="mw-page-title-main">Joseph Lennox Pawan</span> Trinidadian bacteriologist

Joseph Lennox Donation Pawan MBE was a Trinidadian bacteriologist who was the first person to show that rabies could be spread by vampire bats to other animals and humans.

<span class="mw-page-title-main">Infrared sensing in vampire bats</span>

Vampire bats have developed a specialized system using infrared-sensitive receptors on their nose-leaf to prey on homeothermic (warm-blooded) vertebrates. Trigeminal nerve fibers that innervate these IR-sensitive receptors may be involved in detection of infrared thermal radiation emitted by their prey. This may aid bats in locating blood-rich areas on their prey. In addition, neuroanatomical and molecular research has suggested possible similarities of IR-sensing mechanisms between vampire bats and IR-sensitive snakes. Infrared sensing in vampire bats has not yet been hypothesized to be image forming, as it was for IR-sensitive snakes. While the literature on IR-sensing in vampire bats is thin, progress continues to be made in this field to identify how vampire bats can sense and use infrared thermal radiation.

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