Spine (zoology)

Source: Wikipedia, the free encyclopedia.

In a zoological context, spines are hard, needle-like anatomical structures found in both vertebrate and invertebrate species. The spines of most spiny mammals are modified hairs, with a spongy center covered in a thick, hard layer of keratin and a sharp, sometimes barbed tip.

Occurrence

Mammals

The defensive spines on a porcupine

Spines in mammals include the prickles of

spiny bandicoots, and on echidnas (of the monotremes
).

An ancient

, had extremely long spines on its backbone that were joined together with a web of skin that formed a sail-like structure.

Many mammalian species, like cats and fossas,[1][2] also have penile spines.

The Mesozoic

eutriconodont mammal Spinolestes already displayed spines similar to those of modern spiny mice.[3]

Fish

ray-finned fish
lobe-finned fish
lionfish
, with venomous spines
The stinger on a stingray's tail

Spines are found in the

folding fan-like fin made of spreading bony spines called lepidotrichia or "rays" covered by thin stretches of skin
.

In the other bony fish

.

Some fish, such as

dermal denticles
.

The

Invertebrates

copulatory organ on a male parasitic flatworm, Lethacotyle vera

Defensive spines are also found in

Pitar lupanaria
.

Many species of arthropods also have spine-like protrusions on their bodies for defensive purposes. For example, the

setae on many caterpillars and New World tarantulas are essentially tiny detachable spines that can cause severe irritation upon contact. Those on the Lonomia caterpillars are venomous and can cause lethal coagulopathy, hemolysis and kidney failure
.

Spines are also found in internal organs in

copulatory spines in the male or female organs of certain flatworms
.

Function

In many cases, spines are a defense mechanism that help protect the animal against potential predators. Because spines are sharp, they can puncture skin and inflict pain and damage which may cause the predator to avoid that species from that point on.

The spine of some animals are capable of injecting venom. In the case of some large species of stingray, a puncture with the barbed spine and the accompanying venom has occasionally been fatal to humans.

Animals such as porcupines are considered aposematic, because their spines warn predators that they are dangerous and potentially toxic.[5] Porcupines rattle their quills as a warning to predators, much like rattlesnakes.[5]

Treating injuries caused by spines

Because many species of fish and invertebrates carry venom within their spines, a rule of thumb is to treat every injury as if it were a snake bite. Venom can cause intense pain, and can sometimes result in death if left untreated.[6]

On the other hand, being pricked by a porcupine quill is not dangerous, and the quills are not poisonous. The quill can be removed by gently but firmly pulling it out of the skin. The barbed tip sometimes breaks off, but it works its way out through the skin over time.[7]

Human uses

Common uses for animal spines include:

  • Jewelry
    • Bracelets, earrings, and necklaces made from these spines are very common
    • Tribes from around the world use porcupine quills as jewelry for their body modification i.e. through the nose
  • Pens
    • Some of the earliest pens were made from quills
  • Quillwork, a form of textile embellishment traditionally practiced by Indigenous peoples of North America that employs the quills of porcupines as an aesthetic element

Sometimes :

  • Brush

References

  1. .
  2. ^ Dufault, Danielle (July 9, 2018). "Fossa: the King of Madagascar". Youtube. Retrieved April 14, 2021. {{cite web}}: Check |url= value (help)
  3. ^ Thomas Martin, Jesús Marugán-Lobón, Romain Vullo, Hugo Martín-Abad, Zhe-Xi Luo & Angela D. Buscalioni, A Cretaceous eutriconodont and integument evolution in early mammals, Nature 526, 380–384 (15 October 2015) doi:10.1038/nature14905 Received 05 March 2015 Accepted 13 July 2015 Published online 14 October 2015
  4. .
  5. ^ .
  6. ^ "Wilderness Survival". Dangerous Fish and Mollusks. retrieved 2012-03-20
  7. ^ Conger, Cristen. "What's the best way to remove porcupine quills?". http://animals.howstuffworks.com/mammals/remove-porcupine-quills1.htm . retrieved 2012-03-20