They have completely different life cycles and entirely different anatomy, with salamanders not even possessing external ears or keratinized claws, unlike lizards which have both. In the same way both sharks and dolphins have a similar streamlined body shape, both lizards and salamanders evolved to have four legs and a tail. Reptiles are actually more closely related to birds and mammals than amphibians like salamanders.
This is the most noticeable difference between the two and the most easily identifiable. Salamanders are covered in a mucous layer reminiscent of their juvenile stage that keeps moisture in their skin. Unlike lizards that have obvious outer ear openings, salamanders lack both an outer and a middle ear.
Lizards possess claws in order to climb, run, and attack other animals. However, the salamander prefers to stay hidden and safe and are much less confrontational than lizards as well. To tell the difference between the tracks of a salamander and a lizard, you simply need to count the toes!
Salamanders belong to a group of animals called amphibians, which includes frogs as well. Amphibians begin their life cycle in the water and undergo a metamorphosis from their juvenile water-breathing forms to adult air-breathing forms. Lizards, on the other hand, have leathery and partially calcified eggs that are typically buried in sand or dirt. Lizards tend to be longer-limbed and they move in more of a creeping motion.
Salamanders, on the other hand, move incredibly quickly. Salamanders can sense vibrations but are unable to hear. They are generally voiceless, although some utter faint squeaks. Salamanders have 2 nostrils connected to the mouth, eyes often with movable lids, a mouth with fine teeth, a tongue often protrusible, a skeleton largely bony, a 3-chambered heart with 2 auricles and one ventricle, and body temperature dependent on environment.
They breathe by gills, lungs, mouth lining, and skin, sometimes in combination, sometimes separately. Members of the stream, spring, and damp woodland dwelling family Plethodontidae lack lungs and breathe through the skin and mouth.
Fertilization may be external or internal internal in all Canadian species. When internal, the male deposits jellylike capsules of sperm; the female picks them up in the lips of the cloaca chamber through which eggs pass. The eggs are fertilized as they are expelled. All Canadian species lay eggs, the number laid and incubation period varying with each species. The mudpuppy, which spends its entire life in water, lays its eggs under stones where they are guarded by the female.
Adult and larvae red-spotted newts Notophthalmus viridescens live in water, but in most parts of their range after the young grow legs they loose their gills, leave the water and spend a year or more on land. At this stage, they are referred to as "efts" At maturity, they return to ponds to breed.
In the lungless salamanders, some lay their eggs under stones in water two lined or in moist places along brooks dusky and spring ; others lay in sphagnum above woodland pools four toed , or in damp, rotted logs redback, wandering and Ensatina. Mole salamanders family Ambystomatidae deposit eggs in ponds in a jellylike mass attached to vegetation.
Some species go to ponds, ditches and lakes in early spring to lay eggs, while stream and woodland species may not deposit until summer. Water-hatching young breathe through gills and may retain these for several years before transforming into land dwelling adults.
In a few species under certain environmental conditions eg, tiger salamander Ambystoma tigrinum and red spotted newt , the larval gills are retained after maturity and these adults remain in the water.
A complication in species recognition where ranges overlap occurs with Ambystoma species: laterale will hybridize with both jeffersonianum and texanum , and the laterale X texanum hybrid in turn interbreeds with tigrinum where it occurs on US islands in Lake Erie, just south of Canada. All crosses produce triploids ie, containing an extra set of chromosomes , which are most often female and mate with males of either parent species but usually produce solely triploid females like themselves.
Some crosses produce diploid ie, normal number of chromosomes or even tetraploids or pentaploids. The mixing is further complicated by the hybrids having mitochondrial ie, outside the cell nucleus contribution from yet another salamander, A. Since they are unable to survive freezing temperatures and must burrow in the earth or under leaf litter where frost does not penetrate, terrestrial salamander species hibernate during colder months.
Most aquatic species are probably active year round. Most nonaquatic salamanders are active at night, usually during wet or damp periods; dry air and warm sun would quickly dehydrate them. During the spring breeding season, mole salamanders may be found moving at night across highways to ditches and ponds, where they can be observed with the aid of a flashlight.
If sticks or rocks are gently turned over along or in a rocky brook or around a spring, stream salamanders and spring salamanders may often be discovered. Salamanders are closer related to frogs despite how different frogs and salamanders look. Lizards are a type of reptile; they have dry skin with scales and are purely terrestrial.
The largest salamander is the Chinese giant salamander Andrias davidianus. It can be up to 6 feet long! Sadly, they are endangered and very few live long enough to reach that size. Some of the factors that are influencing its population decline are loss of habitat and habitat destruction, especially with the building of dams.
They are also a food source for many people and even considered a delicacy in some areas. The smallest salamander is probably Thorius arboreas, a member of the Minute salamanders. There are several salamanders in the Minute genus, all of which are really, really tiny. Thorius arboreas is found in Mexico and can be as small as 16mm! Animals that have bright colors are often toxic! In some cases the animals might not be toxic but is copying a similar animal that is toxic mimicry.
Most newts have some kind of toxin they secrete through their skin. They also have various defensive postures to show off their bright colors so predators know to avoid eating them. Caecilians are long slender limbless amphibians that look like a cross between a worm and a snake.
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