Autohaemorrhaging
Autohaemorrhaging, or reflex bleeding, is the action of animals deliberately ejecting
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.[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
- spittlebugs Prosapia bicincta and Prosapia ignipectus[7]
- Lepidoptera
- Arctia caja, which mixes haemolymph with glandular products (neurotoxic choline esters).[8]
- Orthoptera
- milkweedon which they feed.
- Katydids, including Eugasterspecies
- Armoured ground crickets
- Enyaliopsis nyala
- Plecoptera
- Stonefly larvae [citation needed]
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).[9]
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.[10]
- European grass snake (Natrix natrix), which secretes blood from the lining of the mouth while playing dead.[11]
- Long-nosed snake (Rhinocheilus lecontei), which exudes blood from the cloaca.[12]
- Eastern hognose snake (Heterodon platirhinos), which emits blood from the cloacal region.[12]
- Plain-bellied water snake (Nerodia erythrogaster), which releases blood from the mouth.[12]
- 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.[13] Autohaemorrhaging may result in dehydration. The ejection of blood puts organisms at risk of cannibalism from conspecifics.[14]
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See also
- Autothysis
- Haemorrhage
References
- ^ a b Iftime, Alexandru; Iftime, Oana (January 2014). "Thanatosis and autohaemorrhaging in the Aesculapian Snake Zamenis". Herpetozoa. 26 (3–4): 173–174 – via Zobodat.
- ISSN 1469-7998.
- S2CID 18599346.
- ^ 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.
- S2CID 249480941.
- ^ The Alkaloids: chemistry and physiology, Volume 31 By Arnold Brossi
- .
- ^ V.H. Resh, R.T. Cardé (2003) Encyclopedia of Insects. p. 168
- S2CID 86061329.
- .
- PMID 17516791.
- ^ a b c 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.
- S2CID 63715931.
- S2CID 18599346.
External links
Media related to Autohaemorrhaging at Wikimedia Commons
