Spine (zoology)

This article is about needle-like growths in animals. For backbone, see Vertebral column. For other uses, see spine (disambiguation).

A spine is a hard, thorny or needle-like structure such as the ray of a fin, a quill, or a ridge on a bone, which occurs on many animals such as the Porcupine, Hedgehogs, and Stingrays, as well as plants such as cacti, and roses. Animals such as Porcupines and sea urchins grow spines as a self-defense mechanism. Spines are sharp and can puncture skin and inflect a lot of damage, and many are capable of injecting venom which can be fatal in the case of the Stringray. Spines are modified hair, with a spongy center covered in a thick, hard layer of keratin, and a sharp barbed tip. Other animals with spines are Scorpion fish, spiny mice, Blue-ringed octopus and the Portuguese man-of-war. Also, based on the fossil record, many Dinosaurs also adorned spines on their bodies.

Defense Mechanism

• Agrawal et al.(2000) found that plants use spines, prickles, and thorns as a defense mechanisms against herbivores, but these spines seem to have little effect on pollinators, which they need to survive and reproduce.
• Animals on the other hand, use these spines as a defense against predators. These animals are considered aposematic, because their spines tell predators that they are dangerous, and potentially toxic (Speed, & Ruxton 2005).

Treating Spine-related Injuries

• Because many species of fish and invertebrate carry venom within their spines, a general rule of thumb is to treat all injuries as if it were a snake bite. This venom can cause intense pain, and can result in death if left untreated.

• If you're pricked with a spine such as a Porcupine quill, you can remove it by gently, but firmly pulling it from your skin. These quills are not poisonous, and it fact contain antibiotics. The barbed tip may break off, but like a splinter, your body will eventual push it out.
  • Note: porcupines rattle their quills as a warning much like rattle snakes, so if they're rattling you should stay away.

• Thorns and prickles can hurt a lot but in most cases won't cause much damage.

References

1. "Wilderness Survival". http://www.wilderness-survival.net/fish-2.php. retrieved 2012-03-20

2. Conger, Cristen. "What's the best way to remove porcupine quills?". http://animals.howstuffworks.com/mammals/remove-porcupine-quills1.htm. retrieved 2012-03-20

3. Agrawal, A, A., Rudgers, A, J., Botsford, W, L., Cutler, S., Gorin, B, J., Lundquist, C, J., Spitzer, W, B., & Swann, L, A. (2000). Benefits and Constraints on Plant Defense against Herbivores: Spines Influence the Legitimate and Illegitimate Flower Visitors of Yellow Star Thistle, Centaurea solstitialis L. (Asteraceae). JSTOR, 45(1), 1-5. http://www.jstor.org/discover/10.2307/3672545?uid=3739392&uid=2129&uid=2&uid=70&uid=3737720&uid=4&sid=55926645943. retrieved 2012-03-20

4. Speed, M, P., Ruxton, G, D.(2005). Warning displays in spiny animals: one (more) evolutionary route to aposematism. Evolution, 59(12), 2499-2508. http://www.ncbi.nlm.nih.gov/pubmed/16526498. retrieved 2012-03-20