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منذ 5 ساعات نشر في ٢٠٢٦/٠٧/١٠ م

In California, the palatable yellow-eyed salamander (Ensatina eschscholtzii) closely resembles the toxic California newt (Taricha torosa) and the rough-skinned newt (Taricha granulosa), whereas in other parts of its range, it is cryptically colored.

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منذ 1 أيام نشر في ٢٠٢٦/٠٧/٠٩ م

the eastern newt is avoided by birds and snakes, and can survive for up to 30 minutes after being swallowed (later being regurgitated).
The red salamander (Pseudotriton ruber) is a palatable species with a similar coloring to the red eft. Predators that previously fed on it have been shown to avoid it after encountering red efts, an example of Batesian mimicry.

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منذ 6 أيام نشر في ٢٠٢٦/٠٧/٠٤ م

Although many salamanders have cryptic colors so as to be unnoticeable, others signal their toxicity by their vivid coloring. Yellow, orange, and red are the colors generally used, often with black for greater contrast. Sometimes, the animal postures if attacked, revealing a flash of warning hue on its underside.

The red eft, the brightly colored terrestrial juvenile form of the eastern newt (Notophthalmus viridescens), is highly poisonous.

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منذ 1 أسابيع نشر في ٢٠٢٦/٠٧/٠٣ م

The Iberian ribbed newt (Pleurodeles waltl) has another method of deterring aggressors. 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.

This action causes the ribs to puncture the body wall, each rib protruding through an orange wart arranged in a lateral row.
When the danger has passed, the ribs retract and the skin heals.

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منذ 1 أسابيع نشر في ٢٠٢٦/٠٧/٠٢ م

Skin secretions of the tiger salamander (Ambystoma tigrinum) fed to rats have been shown to produce aversion to the flavor, and the rats avoided the presentational medium when it was offered to them again.

The fire salamander (Salamandra salamandra) has a ridge of large granular glands down its spine which are able to squirt a fine jet of toxic fluid at its attacker. By angling its body appropriately, it can accurately direct the spray for a distance of up to 80 cm (30 in).

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منذ 1 أسابيع نشر في ٢٠٢٦/٠٧/٠١ م

When attacked by a predator, a salamander may position itself to make the main poison glands face the aggressor. Often, these are on the tail, which may be waggled or turned up and arched over the animal's back.

The sacrifice of the tail may be a worthwhile strategy, if the salamander escapes with its life and the predator learns to avoid that species of salamander in the future.

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منذ 1 أسابيع نشر في ٢٠٢٦/٠٦/٣٠ م

Salamanders have thin skins and soft bodies, move rather slowly and might appear vulnerable to opportunistic predation, but have several effective lines of defense.
Mucus coating on damp skin makes them difficult to grasp, and the slimy coating may have an offensive taste or be toxic.

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منذ 2 أسابيع نشر في ٢٠٢٦/٠٦/٢٩ م

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. They feed on algae and other soft-plants in the wild, and easily eat offered lettuce.

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منذ 2 أسابيع نشر في ٢٠٢٦/٠٦/٢٧ م

An aquatic salamander lacks muscles in the tongue, and captures its prey in an entirely different manner. It grabs the food item, grasps it with its teeth, and adopts a kind of inertial feeding.

This involves tossing its head about, drawing water sharply in and out of its mouth, and snapping its jaws, all of which tend to tear and macerate the prey, which is then swallowed.

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منذ 2 أسابيع نشر في ٢٠٢٦/٠٦/٢٦ م

High-speed cinematography shows how the tiger salamander (Ambystoma tigrinum) positions itself with its snout close to its prey. Its mouth then gapes widely, the lower jaw remains stationary, and the tongue bulges and changes shape as it shoots forward.

The protruded tongue has a central depression, and the rim of this collapses inward as the target is struck, trapping the prey in a mucus-laden trough. Here it is held while the animal's neck is flexed, the tongue retracted and jaws…
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منذ 2 أسابيع نشر في ٢٠٢٦/٠٦/٢٥ م

A terrestrial salamander catches its prey by flicking out its sticky tongue in an action that takes less than half a second. In some species, the tongue is attached anteriorly to the floor of the mouth, while in others, it is mounted on a pedicel.

It is rendered sticky by secretions of mucus from glands in its tip and on the roof of the mouth.

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منذ 2 أسابيع نشر في ٢٠٢٦/٠٦/٢٤ م

When struggling prey is advanced into the salamander's mouth, the teeth tips relax and bend in the same direction, encouraging movement toward the throat, and resisting the prey's escape.

Many salamanders have patches of teeth attached to the vomer and the palatine bones in the roof of the mouth, and these help to retain prey. All types of teeth are resorbed and replaced at intervals throughout the animal's life.

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منذ 2 أسابيع نشر في ٢٠٢٦/٠٦/٢٣ م

Most species of salamander have small teeth in both their upper and lower jaws. Unlike frogs, even the larvae of salamanders possess these teeth.

Although larval teeth are shaped like pointed cones, the teeth of adults are adapted to enable them to readily grasp prey.

The crown, which has two cusps (bicuspid), is attached to a pedicel by collagenous fibers. The joint formed between the bicuspid and the pedicel is partially flexible, as it can bend inward, but not…
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منذ 3 أسابيع نشر في ٢٠٢٦/٠٦/٢٢ م

Cannibalism sometimes takes place, especially when resources are short or time is limited. Tiger salamander tadpoles in ephemeral pools sometimes resort to eating each other, and are seemingly able to target unrelated individuals.

Adult blackbelly salamanders (Desmognathus quadramaculatus) prey on adults and young of other species of salamanders, while their larvae sometimes cannibalise smaller larvae.

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منذ 3 أسابيع نشر في ٢٠٢٦/٠٦/٢٠ م

Salamanders are opportunistic predators. They are generally not restricted to specific foods, but feed on almost any organism of a reasonable size.

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

Smaller dusky salamanders (Desmognathus) in the Appalachian Mountains, their diet includes earthworms, flies, beetles, beetle larvae, leafhoppers, springtails, moths, spiders,…
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منذ 3 أسابيع نشر في ٢٠٢٦/٠٦/١٩ م

The external gills seen in salamanders differs greatly from that of amphibians with internalized gills. Unlike amphibians with internalized gills which typically rely on the changing of pressures within the buccal and pharyngeal cavities to ensure diffusion of oxygen onto the gill curtain, neotenic salamanders such as Necturus use specified musculature, such as the levatores arcuum, to move external gills to keep the respiratory surfaces constantly in contact with new oxygenated water.

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منذ 3 أسابيع نشر في ٢٠٢٦/٠٦/١٨ م

A dissected view of the levatores arcuum muscles in a Necturus maculosus specimen. These move the external gills, as a means of respiration.
In the Necturus, external gills begin to form as a means of combating hypoxia in the egg as egg yolk is converted into metabolically active tissue.

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…
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منذ 3 أسابيع نشر في ٢٠٢٦/٠٦/١٧ م

In the amphiumas, metamorphosis is incomplete, and they retain one pair of gill slits as adults, with fully functioning internal lungs.

Some species that lack lungs respire through gills. In most cases, these are external gills, visible as tufts on either side of the head. Some terrestrial salamanders have lungs used in respiration, although these are simple and sac-like, unlike the more complex organs found in mammals. Many species, such as the olm, have both lungs and gills as…
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منذ 3 أسابيع نشر في ٢٠٢٦/٠٦/١٦ م

In the lungless salamanders (family Plethodontidae and the clawed salamanders in the family of Asiatic salamanders), no lungs or gills are present, and gas exchange mostly takes place through the skin, known as cutaneous respiration, supplemented by the tissues lining the mouth. To facilitate this, these salamanders have a dense network of blood vessels just under the skin and in the mouth.

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منذ 4 أسابيع نشر في ٢٠٢٦/٠٦/١٥ م

When present in adult salamanders, lungs vary greatly among different species in size and structure. In aquatic, cold-water species like the torrent salamanders (Rhyacotriton), the lungs are very small with smooth walls, while species living in warm water with little dissolved oxygen, such as the lesser siren (Siren intermedia), have large lungs with convoluted surfaces.

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منذ 4 أسابيع نشر في ٢٠٢٦/٠٦/١٣ م

Some neotenic species such as the mudpuppy (Necturus maculosus) retain their gills throughout their lives, but most species lose them at metamorphosis. The embryos of some terrestrial lungless salamanders, such as Ensatina, that undergo direct development, have large gills that lie close to the egg's surface.

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منذ 4 أسابيع نشر في ٢٠٢٦/٠٦/١٢ م

Respiration differs among the different species of salamanders, and can involve gills, lungs, skin, and the membranes of mouth and throat. Larval salamanders breathe primarily by means of gills, which are usually external and feathery in appearance. Water is drawn in through the mouth and flows out through the gill slits.

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منذ 4 أسابيع نشر في ٢٠٢٦/٠٦/١١ م

Similar clicking behaviour was observed in two European newts Lissotriton vulgaris and Ichthyosaura alpestris in their aquatic phase.

Vocalization in salamanders has been little studied and the purpose of these sounds is presumed to be the startling of predators.

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منذ 4 أسابيع نشر في ٢٠٢٦/٠٦/١٠ م

The arboreal salamander can squeak using a different mechanism; it retracts its eyes into its head, forcing air out of its mouth. The ensatina salamander occasionally makes a hissing sound, while the sirens sometimes produce quiet clicks, and can resort to faint shrieks if attacked.

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