Instruct: Given a question, retrieve documents that answer the question.
Query: How do newts breathe?
When newts are inactive or in oxygen-rich environments, respiration can be done through their skin which accounts for 74% of the cutaneous respiration. However, oxygen-poor environments, such as stagnant ponds, pose a threat to the survival of larval newts. This is because oxygen molecules do not readily dissolve in water, and as "T. carnifex" is an immobile animal, extracting oxygen from water is difficult. Newts consequently have external gills at birth that persist until metamorphosis, which assists survival in low-oxygen conditions.
Fish from multiple groups can live out of the water for extended time periods. Amphibious fish such as the mudskipper can live and move about on land for up to several days, or live in stagnant or otherwise oxygen depleted water. Many such fish can breathe air via a variety of mechanisms. The skin of anguillid eels may absorb oxygen directly. The buccal cavity of the electric eel may breathe air. Catfish of the families Loricariidae, Callichthyidae, and Scoloplacidae absorb air through their digestive tracts. Lungfish, with the exception of the Australian lungfish, and bichirs have paired lungs similar to those of tetrapods and must surface to gulp fresh air through the mouth and pass spent air out through the gills. Gar and bowfin have a vascularized swim bladder that functions in the same way. Loaches, trahiras, and many catfish breathe by passing air through the gut. Mudskippers breathe by absorbing oxygen across the skin (similar to frogs). A number of fish have evolved so-called accessory breathing organs that extract oxygen from the air. Labyrinth fish (such as gouramis and bettas) have a labyrinth organ above the gills that performs this function. A few other fish have structures resembling labyrinth organs in form and function, most notably snakeheads, pikeheads, and the Clariidae catfish family.
"T. carnifex" faces an interesting challenge, one that all air-breathing aquatic newts must face: the temperature variance between the land phase and the aquatic phase. Since water has a heat capacity 3500 times greater and a thermal conductance 23 times greater than air, small ectotherms such as the Italian crested newt are likelier to have a more variable body temperature than strictly terrestrial organisms. Many ectotherms possess the ability to reversibly alter their preferred body temperature based upon the seasonal changes the newt experiences, which means that their optimal thermal range is quite wide. They respond to variance in temperature by employing either behavioural or physiological changes. Some changes in body temperature are unavoidable, however, depending on how much solar radiation is available.
During the subsequent few months, the larvae undergo metamorphosis, during which they develop legs, and the gills are absorbed and replaced by air-breathing lungs. Some species, such as the North American newts, also become more brightly coloured during this phase. Once fully metamorphosised, they leave the water and live a terrestrial life, when they are known as "efts". Only when the eft reaches adulthood will the North American species return to live in water, rarely venturing back onto the land. Conversely, most European species live their adult lives on land and only visit water to breed.
Eastern newts eat a variety of prey, such as insects, small mollusks and crustaceans, young amphibians, worms, and frog eggs.
Although eastern newts are widespread throughout North America, they, like many other species of amphibians are increasingly threatened by several factors including, habitat fragmentation, climate change, invasive species, over-exploitation, and emergent infectious diseases. Wild eastern newts are known hosts of "Batrachochytrium dendrobatidis" and "Ranavirus". They are also highly susceptible to the newly emergent chytrid fungus "Batrachochytrium salamandrivorans".
The smooth newt, also known as the common newt (Lissotriton vulgaris; formerly Triturus vulgaris) is a species of amphibian, the most common newt of the genus "Lissotriton". It is found throughout Europe, except the far north, areas of Southern France and the Iberian Peninsula.
The rough skinned newt uses a form of chemical based avoidance behavior to evade being eaten by predators, mainly the common garter snake. The snakes, after swallowing, digesting, and metabolizing a rough-skinned newt, release a chemical signature. This stimulus can be detected by a nearby newt and trigger an avoidant response, which allows them to minimize predation risks. In this way, newts are able to differentiate whether a snake is resistant or sensitive to the toxin in order to avoid being preyed upon. However, newts do not avoid the corpses of a recently digested newt that has been left to decompose. This behavior is unlike salamanders that have been documented in avoiding other damaged salamanders.
The Queensland lungfish has very complex courtship behavior made up of three distinct phases. The first is the searching phase, when the fish will range over a large area, possibly searching for potential spawning sites. A pair of fish will perform circling movements at the surface of the water close to beds of aquatic plants. They breathe air more frequently and more noisily than normal, possibly reflecting a greater physiological requirement for oxygen. Individual fish have been observed to breathe air at regular intervals of about 20 minutes, with air breathing accompanied by a distinct loud burp made in the air. The noisy breathing may be a form of a mating call. The lungfish seem to do their noisy breathing in concert, even responding to each other, but never in close vicinity of where the eggs are laid.
The skin of amphibians is a major site of respiration in all species for which measurements are available. Cutaneous respiration is the sole respiratory mode of lungless salamanders (family Plethodontidae) which lack lungs entirely yet constitute the largest family of salamanders. Cutaneous respiration in frogs and other amphibians may be the primary respiratory mode during colder temperatures.
The blood of a cuttlefish is an unusual shade of green-blue, because it uses the copper-containing protein haemocyanin to carry oxygen instead of the red, iron-containing protein haemoglobin found in vertebrates' blood. The blood is pumped by three separate hearts: two branchial hearts pump blood to the cuttlefish's pair of gills (one heart for each), and the third pumps blood around the rest of the body. Cuttlefish blood must flow more rapidly than that of most other animals because haemocyanin carries substantially less oxygen than haemoglobin. Unlike most other mollusks, cephalopods like cuttlefish have a closed circulatory system.
Lungfish are freshwater rhipidistian fish belonging to the subclass Dipnoi. Lungfish are best known for retaining characteristics primitive within the Osteichthyes, including the ability to breathe air, and structures primitive within Sarcopterygii, including the presence of lobed fins with a well-developed internal skeleton.
Only six amphibians and four land reptiles are native to Scotland. The amphibians include three species of newt: the great crested, of which fewer than 1,000 individuals survive; the smooth, and the palmate. The other amphibians are the common toad, the natterjack toad, found in only four locations in the south-west, and the common frog. A single alien amphibian is known in Scotland, the Alpine newt, a recent escapee confined to the Edinburgh area.
Djoko Iskandar, an Indonesian zoologist, first described the Bornean flat-headed frog based on a single specimen. However, he did not know the frog was lungless until he was in the field with David Bickford's expedition. Bickford "et al." were able to dissect some of the specimens and discovered for the first time that the frogs had no lungs. The frog breathes entirely through its skin, and its internal organs (the stomach, spleen and the liver) take up much of the space which normally would be filled by the lungs. By retaining the lunglessness of their tadpole stage, the frogs are much flatter than typical frogs, which might help absorb oxygen and avoid being swept away in fast streams.
Both flight frogs had electrocardiogram (ECG) electrodes implanted in their thoracic cavities and microelectrodes implanted in their vestibular nerves. The frogs were demotorized by cutting their limb nerves to prevent them from dislodging their implanted electrodes, and to reduce their metabolic rates. With this lowered metabolic activity, the frogs could survive in good health without being fed for as long as one month. Immersion in water allowed the frogs to breathe through their skin. The water medium also helped to move carbon dioxide and heat away from the animals.
The Tana lungfish has a diet not unlike other lungfish, consisting of various mollusks, crabs, prawn, and small fish within its distribution. It can also go for up to 3 1/2 years without any food intake whatsoever. During this time period it behaves much like an estivating fish in that it buries itself in the mud and does not move until more favorable conditions occur.
In most subsequent forms, many of these early ribs have been lost, and in living amphibians and reptiles, there is great variation in rib structure and number. For example, turtles have only eight pairs of ribs, which are developed into a bony or cartilaginous carapace and plastron, while snakes have numerous ribs running along the full length of their trunk. Frogs typically have no ribs, aside from a sacral pair, which form part of the pelvis.
The birds of New Zealand evolved into an avifauna that included a large number of endemic species. As an island archipelago New Zealand accumulated bird diversity and when Captain James Cook arrived in the 1770s he noted that the bird song was deafening. The mix includes species with unusual biology such as the kakapo which is the world's only flightless, nocturnal, lek breeding parrot, but also many species that are similar to neighboring land areas. Some of the more well known and distinctive bird species in New Zealand are the kiwi, kea, takahe, kakapo, mohua, tui and the bellbird. The tuatara is a notable reptile endemic to New Zealand.
Frogs are born with legs that are good for hopping and special pads on their toes to help them climb. In comparison, toads have shorter legs, drier skin, and are less likely to live near water. Most frogs and toads are responsible for controlling the Earth's insect population, since their diet consists mostly of insects and spiders. However, the green eyed-tree frog is also a carnivore. As a tadpole, the frogs mostly consume algae and plants. Frogs have a moist and permeable skin layer covered with mucous glands, which enables them to breathe through their skin, not just their lungs. The layer of mucus that covers them also acts as a shield, protecting them from scratches. The reason frogs have large and protruding eyes is to make up for their lack of a neck. This eye feature allows them to see everything around them. The color scheme of the green-eyed tree frog is to camouflage them from predators. Frogs with bright colors are alerting predators of their poisonous nature.
While resistance to tetrodotoxin is beneficial in acquiring newt prey, there are also costs associated with it as well. Consuming the toxin can lead to reduced speed and sometimes no movement for extended periods of time, along with impaired thermoregulation. The anti-predator display that this species uses demonstrates the idea of an "arms race" between different species and their anti-predator displays. Along the entire geographical interaction of "T. granulosa" and "T. sirtalis", there are patches that correspond to strong coevolution as well as weak or absent coevolution. Populations of "T. sirtalis" that do not live in areas that contain "T. granulosa" contain the lowest amount of tetrodotoxin resistance, while those that do live in the same area contain the highest levels of tetrodotoxin resistance. In populations where tetrodotoxin is absent in "T. granulosa", resistance in "T. sirtalis" is selected against because the mutation causes lower average population fitness. This helps maintain polymorphism within garter snake populations.
When longitudinal muscles in the ampullae contract, valves in the lateral canals close and water is forced into the tube feet. These extend to contact the substrate. Although the tube feet resemble suction cups in appearance, the gripping action is a function of adhesive chemicals rather than suction. Other chemicals and relaxation of the ampullae allow for release from the substrate. The tube feet latch on to surfaces and move in a wave, with one arm section attaching to the surface as another releases. Some starfish turn up the tips of their arms while moving which gives maximum exposure of the sensory tube feet and the eyespot to external stimuli.
The rough-skinned newt ("Taricha granulosa") is a newt known for its strong poison. Habitats of rough-skinned newts are found throughout the West Coast of the United States and British Columbia. Their range extends south to Santa Cruz, California and north to Alaska.
The heart of "Triturus carnifex", like that of most amphibians, consists of two atria and one ventricle. Blood flows from the anterior and posterior caval veins into the right atrium; blood that entered the heart from the left atrium is then expelled out of the ventricle. Newts do not have a coronary artery on the ventricle, due to circulation that is found in the conus arteriosus. Newts contain a special circulatory adaptation that allows them to survive ventricular penetration. Myachi found that when a newt’s ventricle is punctured, the heart will divert the blood directly into an ascending aorta via a duct located between the ventricle and the conus arteriosus. "T.carnifex" begins to regenerate the ventricle by a thickening of the epicardial layer that protrudes to allow the new vessels to form, and concludes with a regeneration of the entire myocardial wall.
Temperature plays a key role in the osmoregulation of the newt. Not only do the changing seasons drive "T. carnifex" either into the water or onto land, it also regulates the release of certain hormones in accordance with the osmotic permeability of the newts' epidermis. Osmotic permeability is dependent on the release of hormones such as prolactin, vasotocin, as well as other thyroidal and internal hormones. Brown et al. experimented on a close relative of "T. carnifex" to determine the effects different environmental conditions have on the newts osmoregulatory systems.
"T. carnifex" are ectotherms. This means that the internal forces of this newt that control the body temperature have almost no importance. They are traditionally called “cold-blooded” although blood has really nothing to do with how these animals thermoregulate. This means that "T. carnifex" will regulate in a way that depends more on behavior. When there is a large range of environmental temperatures, newts are very insensitive to a thermal gradient profile.
Juveniles often disperse to new breeding sites, while the adults in general move back to the same breeding sites each year. The newts do not migrate very far: they may cover around in one night and rarely disperse much farther than . For orientation, the newts likely use a combination of cues including odour and the calls of other amphibians, and orientation by the night sky has been demonstrated in the marbled newt. Activity is highest on wet nights; the newts usually stay hidden during daytime. There is often an increase in activity in late summer and autumn, when the newts likely move closer to their breeding sites. Over most of their range, they hibernate in winter, using mainly subterranean hiding places, where many individuals will often congregate. In their southern range, they may instead sometimes aestivate during the dry months of summer.