Salamander

Researchers hope to reverse engineer the regenerative processes for potential human medical applications, such as brain and spinal cord injury treatment or preventing harmful scarring during heart surgery recovery.

[4] The remarkable ability of salamanders to regenerate is not just limited to limbs but extends to vital organs such as the heart, jaw, and parts of the spinal cord, showing their uniqueness compared to different types of vertebrates.

⁤⁤This has made salamanders an invaluable model organism in scientific research aimed at understanding and achieving regenerative processes for medical advancements in human and animal biology.

[12] An adult salamander generally resembles a small lizard, having a basal tetrapod body form with a cylindrical trunk, four limbs, and a long tail.

Except in the family Salamandridae, the head, body, and tail have a number of vertical depressions in the surface which run from the mid-dorsal region to the ventral area and are known as costal grooves.

The hind limbs are extracted and push the skin farther back, before it is eventually freed by friction as the salamander moves forward with the tail pressed against the ground.

The sticky layer helps protect against bacterial infections and molds, reduces friction when swimming, and makes the animal slippery and more difficult for predators to catch.

[17] Olfaction in salamanders plays a role in territory maintenance, the recognition of predators, and courtship rituals, but is probably secondary to sight during prey selection and feeding.

Olfactory epithelium in the nasal cavity picks up airborne and aquatic odors, while adjoining vomeronasal organs detect nonvolatile chemical cues, such as tastes in the mouth.

In some permanently aquatic species, they are reduced in size and have a simplified retinal structure, and in cave dwellers such as the Georgia blind salamander, they are absent or covered with a layer of skin.

[20] To find their prey, salamanders use trichromatic color vision extending into the ultraviolet range, based on three photoreceptor types that are maximally sensitive around 450, 500, and 570 nm.

Before mating, they communicate by pheromone signaling; some species make quiet ticking, clicking, squeaks or popping noises,[26] perhaps by the opening and closing of valves in the nose.

[33] Molecular changes in the mudpuppy during post-embryonic development primarily due to the thyroid gland prevent the internalization of the external gills as seen in most salamanders that undergo metamorphosis.

[37] Large species such as the Japanese giant salamander (Andrias japonicus) eat crabs, fish, small mammals, amphibians, and aquatic insects.

[47] Though frequently feeding on slow-moving animals like snails, shrimps and worms, sirenids are unique among salamanders for having developed herbivory speciations, such as beak-like jaw ends and extensive intestines.

Its skin exudes a poisonous, viscous fluid and at the same time, the newt rotates its sharply pointed ribs through an angle between 27 and 92°, and adopts an inflated posture.

The latter is restricted to the slightly cooler and wetter conditions in north-facing cove forests in the southern Appalachians, and to higher elevations above 900 m (3,000 ft), while the former is more adaptable, and would be perfectly able to inhabit these locations, but some unknown factor seems to prevent the two species from co-existing.

[69] Many salamanders do not use vocalisations,[70] and in most species the sexes look alike, so they use olfactory and tactile cues to identify potential mates, and sexual selection occurs.

The tadpole has three pairs of external gills, no eyelids, a long body, a laterally flattened tail with dorsal and ventral fins and in some species limb-buds or limbs.

[88] Habitat loss, silting of streams, pollution and disease have all been implicated in the decline and a captive breeding programme at Saint Louis Zoo has been successfully established.

Due to its proximity to Mexico City, officials are currently working on programs at Lake Xochimilco to bring in tourism and educate the local population on the restoration of the natural habitat of these creatures.

[91] This proximity is a large factor that has impacted the survival of the axolotl, as the city has expanded to take over the Xochimilco region in order to make use of its resources for water and provision and sewage.

Evidence points toward a historical bottlenecking of Ambystoma that contributes to the variation issues and no longer a large genetic pool for it to pull from, thus raising concern for inbreeding due to lack of gene flow.

Common species such as the tiger salamander and the mudpuppy are being given hormones to stimulate the production of sperm and eggs, and the role of arginine vasotocin in courtship behaviour is being investigated.

A 2005 molecular phylogeny, based on rDNA analysis, suggested that the first divergence between these three groups took place soon after they had branched from the lobe-finned fish in the Devonian (around 360 million years ago), and before the breakup of the supercontinent Pangaea.

[117][118] The mythical ruler Prester John supposedly had a robe made from alleged salamander hair, in fact asbestos fibre, already known by ancient Greece and Rome (the linum vivum of Pliny the Elder Naturalis historia, 19, 4).

For example, according to Tabari, one of the curious items belonging to Khosrow II Parviz, the great Sassanian king (r. 590–628), was a napkin (Persian: منديل) that he cleaned simply by throwing it into fire.

[131] Researchers from the Australian Regenerative Medicine Institute have found that when macrophages were removed, salamanders lost their ability to regenerate and instead formed scar tissue.

If the processes involved in forming new tissue can be reverse engineered into humans, it may be possible to heal injuries of the spinal cord or brain, repair damaged organs and reduce scarring and fibrosis after surgery.

[134] Later research by Slovenian anthropologist Miha Kozorog (University of Ljubljana) paints a very different picture—Salamander in brandy appears to have been traditionally seen as an adulterant, one which caused ill health.

X-ray image of salamander
Sirens have an eel-like appearance.
The front part of the olm 's head carries sensitive chemo-, mechano-, and electroreceptors.
Biofluorescence can be observed across various salamander species
Salamanders need moist environments to respire through their skin.
A dissected view of the levatores arcuum muscles in a Necturus maculosus specimen. These (shown in the purple circles) move the external gills, as a means of respiration.
The head of a tiger salamander
A fire salamander 's striking black and yellow pattern warns off predators
Sierra newt amplexus found in stream at Woolman Semester in Nevada County, California
Embryonic development of a salamander, filmed in the 1920s
Neotenic axolotl , showing external gills
The threatened hellbender
A salamander unharmed in the fire, 1350
Ukiyo-e print by Utagawa Kuniyoshi (1797–1861) depicting a giant salamander being stabbed by the samurai Hanagami Danjō no jō Arakage