Autohaemorrhaging

Horned lizard showing evidence of autohaemorrhaging

Autohaemorrhaging, or reflex bleeding, is the action of animals deliberately ejecting blood from their bodies. Autohaemorrhaging has been observed as occurring in two variations. ^[1] In the first form, blood is squirted toward a predator. The blood of these animals usually contains toxic compounds, making the behaviour an effective chemical defense mechanism. In the second form, blood is not squirted, but is slowly emitted from the animal's body. This form appears to serve a deterrent effect, and is used by animals whose blood does not seem to be toxic. ^[1] Most animals that autohaemorrhage are insects, but some reptiles also display this behaviour. ^[2]

Some organisms have shown an ability to tailor their autohaemorrhaging response. Armoured crickets will projectile autohaemorrhage over longer distances when attacked from the side, compared to being attacked from an overhead predator. ^[3]

Insects

Several orders of insects have been observed to utilize this defence mechanism.

• Beetles
  • Meloidae (blister beetles) – their haemolymph contains cantharidin that they sequester from plants on which they feed. One of the known species is Meloe americanus . ^[4]
  • Tenebrionidae (darkling beetles) - larvae of Asbolus verrucosus have been observed to autohaemorrhage while they feign death. ^[5]
  • Chrysomelidae, incl. Timarcha species - their haemolymph contains anthraquinones.
  • Coccinellidae (ladybird, ladybug or lady beetles) – An alkaloid toxin in the haemolymph is exuded through the joints of the exoskeleton, triggered by mechanical stimulation (such as predator attack). ^[6]
• Hemiptera
  • Cercopidae ^[7] – including spittlebugs Prosapia bicincta and Prosapia ignipectus ^[8]
• Lepidoptera
  • Tiger moth adults, such as Arctia caja , which mixes haemolymph with glandular products (neurotoxic choline esters). ^[9]
• Orthoptera
  • Bushhoppers, such as Dictyophorus spumans , Phymateus viridipes and Phymateus leprosus – their haemolymph contains cardiac glycosides, sequestered from milkweed on which they feed.
  • Katydids, including Eugaster species and Acanthoplus discoidalis ^[10]
• Plecoptera
  • Stonefly larvae ^[11]

Reptiles

A West Indian wood snake displaying autohaemorrhaging. The eyes are fully flooded with blood and some is emerging from the mouth.

Lizards

• Horned lizards (Phrynosomatidae). At least six species of horned lizards are able to squirt an aimed stream of blood from the corners of their eyes, up to 5 feet (1.5 m). ^[12]

Snakes

• West Indian wood snake ( Tropidophis ). Thirteen species have been found to expel blood from the mouth and nostrils while also fully flooding both eyes with blood. ^[13]
• European grass snake ( Natrix natrix ), which secretes blood from the lining of the mouth while playing dead. ^[14]
• Long-nosed snake ( Rhinocheilus lecontei ), which exudes blood from the cloaca. ^[15]
• Eastern hognose snake (Heterodonplatirhinos), which emits blood from the cloacal region. ^[15]
• Plain-bellied water snake ( Nerodia erythrogaster ), which releases blood from the mouth. ^[15]
• Western hognose snake ( Heterodon nasicus ), which releases blood from the mouth.

Consequences of reflexive bleeding

In some cases, the loss of blood can be substantial. Beetles may lose up to 13% of their net body weight as a consequence of expelling haemolymph. ^[16] Autohaemorrhaging may result in dehydration. The ejection of blood puts organisms at risk of cannibalism from other members of their species. ^[17]

An inactive prepupa Asian ladybeetle autohaemorrhaging, resulting from cannibalism by an adult of the same species.

See also

• Autothysis
• Haemorrhage

References

1. Iftime, Alexandru; Iftime, Oana (January 2014). "Thanatosis and autohaemorrhaging in the Aesculapian Snake Zamenis". Herpetozoa. 26 (3–4): 173–174 – via Zobodat.
2. Bateman, P. W.; Fleming, P. A. (2009). "There will be blood: autohaemorrhage behaviour as part of the defence repertoire of an insect". Journal of Zoology. 278 (4): 342–348. doi:10.1111/j.1469-7998.2009.00582.x. ISSN   1469-7998.
3. Bateman, Philip W.; Fleming, Patricia A. (2012-04-26). "Signaling or Not-Signaling: Variation in Vulnerability and Defense Tactics of Armored Ground Crickets (Acanthoplus Speiseri: Orthoptera, Tettigoniidae, Hetrodinae)". Journal of Insect Behavior. 26 (1): 14–22. doi:10.1007/s10905-012-9329-5. ISSN   0892-7553. S2CID   18599346.
4. Young, O.P. (October 1995). "Seasonal Activity of Meloe americanus (Coleoptera: Meloidae) in a Mississippi Old-field Habitat" . Journal of Entomological Science. 30 (4): 434–442. doi:10.18474/0749-8004-30.4.434.
5. Rider, S. Dean; Hostetler, Heather A. (21 June 2022). "Reflex Bleeding in Tonically Immobilized Larvae Causes Debris-Based Camouflage in the Blue Death-Feigning Beetle, Asbolus verrucosus LeConte (Coleoptera: Tenebrionidae)". The Coleopterists Bulletin. 76 (2): 237-247. doi:10.1649/0010-065X-76.2.237. S2CID   249480941.
6. The Alkaloids: chemistry and physiology, Volume 31 By Arnold Brossi
7. Peck, Daniel C. (1 September 2000). "Reflex Bleeding in Froghoppers (Homoptera: Cercopidae): Variation in Behavior and Taxonomic Distribution" . Annals of the Entomological Society of America. 93 (5): 1186–1194. doi:10.1603/0013-8746(2000)093[1186:RBIFHC]2.0.CO;2.
8. Thompson, Vinton; Carvalho, Gervasio S. (2016). "Abrupt Geographical Transition between Aposematic Color Forms in the Spittlebug Prosapia ignipectus(Fitch) (Hemiptera: Cercopidae)". Psyche: A Journal of Entomology. 2016: 1–10. doi: 10.1155/2016/3623092 .
9. V.H. Resh, R.T. Cardé (2003) Encyclopedia of Insects. p. 168
10. van Huis, Arnold (26 March 2022). "Cultural significance of locusts, grasshoppers, and crickets in sub-Saharan Africa". Journal of Ethnobiology and Ethnomedicine. 18 (1): 24. doi: 10.1186/s13002-022-00524-w . ISSN   1746-4269. PMC   8962220 . PMID   35346258.
11. Moore, Kathryn A.; Williams, D. Dudley (1990). "Novel Strategies in the Complex Defense Repertoire of a Stonefly (Pteronarcys dorsata) nymph". Oikos. 57 (1): 49–56. Bibcode:1990Oikos..57...49M. doi:10.2307/3565735. hdl: 1807/762 . ISSN   0030-1299. JSTOR   3565735.
12. Sherbrooke, Wade C.; Middendorf III, George A. (2001). "Blood-Squirting Variability in Horned Lizards (Phrynosoma)" . Copeia. 2001 (4): 1114–1122. doi:10.1643/0045-8511(2001)001[1114:BSVIHL]2.0.CO;2. ISSN   0045-8511. S2CID   86061329.
13. Hoefer, Sebastian; Mills, Sophie; Robinson, Nathan J. (2019). "Autohaemorrhaging in a Bahamian pygmy boa, Tropidophis curtus barbouri". Herpetological Bulletin (150): 39–40. doi: 10.33256/hb150.3940 .
14. Gregory, Patrick T.; Isaac, Leigh Anne; Griffiths, Richard A (2007). "Death feigning by grass snakes (Natrix natrix) in response to handling by human "predators."" . Journal of Comparative Psychology. 121 (2): 123–129. doi:10.1037/0735-7036.121.2.123. ISSN   1939-2087. PMID   17516791.
15. Smith, Donald D.; Pflanz, Deborah J.; Powell, Robert (1993). "Observations of autohemorrhaging in Tropidophis haetianus, Rhinocheilus lecontei, Heterodon platyrhinos, and Nerodia erythrogaster". Herpetological Review. 24: 130–131.
16. Klowden, Marc J. (October 2007). Physiological Systems in Insects. Vol. 2. Elsevier. p. 369. doi:10.1016/c2011-0-04120-0. ISBN   9780124158191. S2CID   63715931.
17. Bateman, Philip W.; Fleming, Patricia A. (2012-04-26). "Signaling or Not-Signaling: Variation in Vulnerability and Defense Tactics of Armored Ground Crickets (Acanthoplus Speiseri: Orthoptera, Tettigoniidae, Hetrodinae)". Journal of Insect Behavior. 26 (1): 14–22. doi:10.1007/s10905-012-9329-5. ISSN   0892-7553. S2CID   18599346.

External links

• Media related to Autohaemorrhaging at Wikimedia Commons