Autohaemorrhaging Explained

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 defence 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. 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
  • Armoured ground crickets^[10]
• Plecoptera
  • Stonefly larvae ^[11]

Reptiles

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 (Heterodon platirhinos), which emits blood from the cloacal region.
• Plain-bellied water snake (Nerodia erythrogaster), which releases blood from the mouth.
• 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]

See also

• Autothysis
• Haemorrhage

Notes and References

1. Iftime. Alexandru. Iftime. Oana. January 2014. Thanatosis and autohaemorrhaging in the Aesculapian Snake Zamenis. Herpetozoa. 26. 3–4. 173–174. 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. en. 278. 4. 342–348. 10.1111/j.1469-7998.2009.00582.x. 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. 10.1007/s10905-012-9329-5. 18599346. 0892-7553.
4. Young . O.P. . Seasonal Activity of Meloe americanus (Coleoptera: Meloidae) in a Mississippi Old-field Habitat . Journal of Entomological Science . October 1995 . 30 . 4 . 434–442 . 10.18474/0749-8004-30.4.434 .
5. Rider . S. Dean . Hostetler . Heather A. . Reflex Bleeding in Tonically Immobilized Larvae Causes Debris-Based Camouflage in the Blue Death-Feigning Beetle, Asbolus verrucosus LeConte (Coleoptera: Tenebrionidae) . The Coleopterists Bulletin . 21 June 2022 . 76 . 2 . 237-247 . 10.1649/0010-065X-76.2.237. 249480941 .
6. https://books.google.com/books?id=yoK7APpgbqoC&dq=Autohaemorrhage+ladybug&pg=PA202 The Alkaloids: chemistry and physiology, Volume 31 By Arnold Brossi
7. Peck . Daniel C. . Reflex Bleeding in Froghoppers (Homoptera: Cercopidae): Variation in Behavior and Taxonomic Distribution . Annals of the Entomological Society of America . 1 September 2000 . 93 . 5 . 1186–1194 . 10.1603/0013-8746(2000)093[1186:RBIFHC]2.0.CO;2 .
8. 10.1155/2016/3623092. Abrupt Geographical Transition between Aposematic Color Forms in the Spittlebug Prosapia ignipectus(Fitch) (Hemiptera: Cercopidae). Psyche: A Journal of Entomology. 2016. 1–10. 2016. Thompson. Vinton. Carvalho. Gervasio S.. free.
9. V.H. Resh, R.T. Cardé (2003) Encyclopedia of Insects. p. 168
10. van Huis . Arnold . Cultural significance of locusts, grasshoppers, and crickets in sub-Saharan Africa . Journal of Ethnobiology and Ethnomedicine . 26 March 2022 . 18 . 1 . 24 . 10.1186/s13002-022-00524-w . free . 35346258 . 8962220 . en . 1746-4269.
11. Moore . Kathryn A. . Williams . D. Dudley . Novel Strategies in the Complex Defense Repertoire of a Stonefly (Pteronarcys dorsata) nymph . Oikos . 1990 . 57 . 1 . 49–56 . 10.2307/3565735 . 3565735 . 1990Oikos..57...49M . 1807/762 . 0030-1299. free .
12. Sherbrooke. Wade C.. Middendorf III. George A.. 2001. https://bioone.org/journals/copeia/volume-2001/issue-4/0045-8511(2001)001[1114:BSVIHL2.0.CO;2/Blood-Squirting-Variability-in-Horned-Lizards-Phrynosoma/10.1643/0045-8511(2001)001[1114:BSVIHL]2.0.CO;2.full Blood-Squirting Variability in Horned Lizards (Phrynosoma)]. Copeia. 2001. 4. 1114–1122. 10.1643/0045-8511(2001)001[1114:BSVIHL]2.0.CO;2. 86061329 . 0045-8511.
13. Hoefer. Sebastian. Mills. Sophie. Robinson. Nathan J.. 2019. Autohaemorrhaging in a Bahamian pygmy boa, Tropidophis curtus barbouri. Herpetological Bulletin. en-gb. 150. 39–40. 10.33256/hb150.3940. free.
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. en. 121. 2. 123–129. 10.1037/0735-7036.121.2.123. 17516791. 1939-2087.
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. Book: Klowden, Marc J.. October 2007. Elsevier. 2. 369. 10.1016/c2011-0-04120-0. 9780124158191. Physiological Systems in Insects. 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. 10.1007/s10905-012-9329-5. 18599346. 0892-7553.