Tiger salamander

in Ambystoma tigrinum Tiger salamanders usually grow to a length of , with the longest found being , and live for around 12–15 years. They are characterized by having markings varying in color on the back of their head, body, and tail. The coloring of these spots range from brownish yellow to greenish yellow, while the rest of their back is black or dark brown. Eastern tiger salamanders emit a bright yellow green fluorescence when illuminated with blue or ultraviolet light. They are smooth bodied, with costal grooves running down their sides to aid in moisture control. They have short snouts, thick necks, strong legs, and lengthy tails. They also utilize specialized foot pads for burrowing through loose soil. Neoteny Some individuals, typically when their aquatic environment is well suited, will retain their larval characteristics and forego metamorphosis. This is known as facultative paedomorphosis, in this case a form of neoteny. These paedomorphic individuals retain their gills and remain aquatic. == Biology ==

Their diet consists largely of small insects, snails, slugs, frogs, aquatic microcrustaceans, and worms, although it is not rare for an adult to turn cannibalistic and consume its own kind. Cannibalism in these salamanders can almost always be traced back to a large volume of competing predators and lack of prey in the area. If the opportunity presents itself, tiger salamanders will even feed on other smaller salamander species, lizards, snakelets (baby snakes), and newborn mice. When threatened, tiger salamanders will display their tail, which will then secrete a thick, white, poisonous substance from their granular skin glands to warn predators. == Habitat ==

Tiger salamanders habitats range from woodlands crowded with conifer and deciduous trees to grassy open fields. After metamorphosis, adult tiger salamanders will migrate to a new territory. Females have been documented to migrate further than males, and larger individuals will migrate further than smaller ones. Tiger salamanders are almost entirely terrestrial as adults, and usually only return to the water to breed. The ideal breeding condition for tiger salamanders ranges from wetlands, such as cattle ponds and vernal pools, to flooded swamps. Tiger salamanders are the widest ranging species of salamander in North America. tiger salamanders have been found in smaller populations across the United States, eastern Mexico, and southern Canada. Though tiger salamanders are not indicators of an ecosystem, they are good indicators of a healthy environment because they need good moist soil to burrow in. In aquatic environments, higher pH and lower water conductivity have both been correlated with a larger population of males specifically. == Breeding ==

Like all ambystomatids, they are extremely loyal to their birthplaces, and will travel long distances to reach them. Tiger salamanders have been shown to travel up to 255 meters after their breeding cycles are complete, which is likely them returning to their original home ranges. Some research has shown that females will travel farther than males. However, a single tiger salamander has only a 50% chance of breeding more than once in its lifetime. In a study conducted in South Carolina, breeding migrations of adult tiger salamanders began in late October or November for males and November through February for females. The tiger salamander's ideal breeding period is somewhere between the late winter and early spring, once the ground is warm enough and the water is thawed. There appears to be no relation between size and mating success. However, females prefer mates with longer tails over mates with shorter tails. She attaches the eggs to secure twigs, grass, and leaves at the bottom of the pool to ensure her eggs' safety. In about 12–15 days time, the eggs will be fully hatched and ready to mature in the pool. Large-scale captive breeding of tiger salamanders has not been accomplished, for unknown reasons. A tiger salamander larva is entirely aquatic, and is characterized by large external gills and are used extensively in the fishing bait and pet trades. Some populations may not metamorphose at all, and become sexually mature while in their larval form. These are called neotenes, and are particularly common where terrestrial conditions are poor. Aquatic individuals of the eastern tiger salamander have been shown to prefer deeper water when compared to other salamander species. == In captivity ==

Tiger salamanders are popular as pets, and suitable for beginner amphibian enthusiasts due to its manageable care requirements and generally docile nature. A single tiger salamander requires a minimum of a 15-gallon tank, while a 20-gallon tank or larger is recommended for housing multiple individuals to provide adequate space for exploration. Although tiger salamanders are non-territorial and can cohabitate peacefully, it is important to monitor them closely for signs of stress or aggression. The enclosure should be well-ventilated and secured with a screened lid to prevent escapes. The optimal temperature range for the habitat is between 60°F and 75°F (15.5°C to 24°C). Humidity levels should be maintained at approximately 70%, which can be monitored using a hygrometer. To achieve and sustain proper humidity, the substrate should be misted daily with water. The substrate should be moist but not saturated. If it becomes overly wet, increased ventilation is recommended. A shallow dish of water should be available at all times, large enough for the salamander to soak in. This water should be cleaned, disinfected, and replaced daily to ensure proper hygiene. A substrate depth of at least 3–4 inches (7.6–10 cm) is recommended to accommodate the salamander's burrowing behavior. Ideally, half of the substrate should remain dry while the other half is slightly moist, allowing the salamander to choose its preferred environment. Suitable substrate materials include cypress mulch, coconut husk fiber, and sphagnum moss. Inappropriate substrates such as sand, gravel, or small bark pieces should be avoided due to the risk of ingestion and internal injury. Reptile carpet is also discouraged, as it can cause skin irritation or abrasions. Handling should be kept to a minimum, as excessive handling can cause stress. When necessary, handlers should wear latex gloves to protect the salamander from the oils and bacteria present on human skin, which can be harmful to amphibians. Tiger salamanders require a varied diet composed primarily of gut-loaded insects and worms. Juveniles should be fed daily to support growth and development, while adults typically require feeding two to three times per week. Care should be taken to avoid overfeeding, particularly with high-fat insects like waxworms, as tiger salamanders are prone to obesity. Common food items include crickets, earthworms, roaches, beetles, superworms, waxworms (occasionally), silkworms, hornworms, phoenix worms, and white worms. A varied diet helps ensure balanced nutrition and prevents dietary deficiencies. == Diseases ==

Although immune themselves, tiger salamanders transmit the fungus Batrachochytrium dendrobatidis, which is a major worldwide threat to most frog species by causing the disease chytridiomycosis. Tiger salamanders also carry ranaviruses, which infect reptiles, amphibians, and fish. Using tiger salamander larvae as fishing bait appears to be a major source of exposure and transport to wild populations. One of these ranaviruses is even named the Ambystoma tigrinum virus (ATV). This ranavirus only transmits to other salamanders and was not found in fish or other amphibians. Severe mortality of tiger salamander larvae sometimes occurs from recurring ranavirus infections. == Conservation status ==

In the southeastern United States, tiger salamander populations are experiencing declines, largely due to deforestation and the destruction of wetland environments; pond disturbance, invasive fish, and road construction threaten the annual population. Research conducted by Harte and Hoffman in the Colorado Rockies suggests acid rain could be a contributing factor. Additional threats include road mortality and contamination of their aquatic habitats. ==Related species==

The California tiger salamander (Ambystoma californiense) (listed at Vulnerable), the barred tiger salamander (A. mavortium), and the plateau tiger salamander (A. velasci) were all once considered subspecies of A. tigrinum, but are now considered separate species. Genetic studies made it necessary to break up the original A. tigrinum population, though some hybridization between groups occurs. The California tiger salamander is now federally listed as an endangered species mostly due to habitat loss; however, very few studies have been performed on this species. The axolotl is also a relative of the tiger salamander. Axolotls live in a paedomorphic state, retaining most characteristics of their larval stage for their entire lifespans. While they never metamorphose under natural conditions, metamorphosis can be induced in them, resulting in a form very similar to the plateau tiger salamander. This is not, however, their natural condition, and dramatically shortens their lifespan. Recently, introgressed tiger salamander (A. tigrinum) DNA was detected in the laboratory axolotl population. ==In society and culture==

On February 2, 2005, Representative Bob Biggins introduced a bill to make the tiger salamander the official state amphibian of Illinois and to make the painted turtle the official state reptile. The bill was signed into law by Governor Rod Blagojevich on July 19, 2005. ==References==