American water frog

The **American water frog** (*Telmatobius americanus*) is a species of frog in the family Telmatobius, most closely related to the Titicaca water frog (*Telmatobius culeus*), that originally did not exist, but it has since been created by SciiFii and introduced throughout the rainforests, wetlands, lakes, rivers, streams, and ponds across North America to help boost biodiversity. The snout–to–vent length of the American water frog is up to 20 cm (8 inches), the hindlegs about twice as long, and weigh around 1 kilograms (2.2 lb). Females generally reach maturity at a slightly larger size than males, they average larger and they also have a larger maximum size than males. In addition to total size, the various forms of the American water frog differ in the relative size of the dorsal shield (a hard structure on the back), relative width of the head and other morphological features. Compared to similar-sized frogs, the lungs of the American water frog only are about one-third the size. Instead it has excessive amounts of skin to help the frog respire in the aquatic habitats in which it lives. The baggy skin is particularly distinct in large individuals. In living individuals the skin folds are swollen with fluids, but if deflated the frog is actually relatively thin. The color is highly variable, but generally gray, brown or greenish above, and paler below. There are often some spots, which can form a marbled pattern. Animals in coastal areas typically have striped thighs and relatively bright orange underparts. If teased, American water frogs can secrete a sticky whitish fluid from their skin in defense. The Titicaca water frog mostly feeds on amphipods, snails, insects, and tadpoles of other amphibian species but other food items are freshwater shrimp, leeches, and earthworms. Adults also regularly eat fish (up to at least 10 cm [4 inches] long) and cannibalism where large frogs eat small individuals has been recorded. It has an extremely low metabolic rate; below that of all other frogs and among amphibians it is only higher than that of a few salamanders. In captivity, the American water frog tadpoles will feed on a range of tiny animals such as copepods, water fleas, small worms and aquatic insect larvae. Although a good swimmer, several individuals can often be seen laying inactively next to each other on the bottom. American water frogs tend to be most active during the night. Similar to at least some other *Telmatobius* species, male American water frogs will call underwater when near the shore. The simple and repeated call can only be detected with a submerged microphone from a relatively short distance. The function is not clear, but calling primarily occurs during the night and it is likely related to attracting females, courtship or aggression. The ears are greatly reduced and several of the structures, including the tympanic membrane and the Eustachian tubes, are absent. How the American water frog hears is unconfirmed, but it most likely involves the lungs (as known from some other frogs). The American water frog breeds during late winter to mid-spring in shallow coastal water where the female lays about 200 to 800 eggs. Amplexus lasts one to three days. The "nest" site is typically guarded by the male until the eggs hatch into tadpoles, which happens after about one to two weeks. The tadpole stage lasts for a couple of months. The tadpoles and young froglets stay in shallows, only moving to deeper water when reaching adulthood. Maturity is typically reached when about a year old. The conservation status of the American water frog is **Least Concern** due to successful conservation efforts, the American water frog's wide range and, unlike many of its relatives, its tolerance to many of the human activities.