general close to the bottom of the water body. Metamorphosis occurs after around three months, again depending on temperature, but some larvae overwinter and metamorphose only in the next year. Paedomorphy Paedomorphy, where adults do not metamorphose and instead retain their gills and stay aquatic, is more common in the alpine newt than in other European newts. It is almost exclusively found in the southern part of the range (but not in the Cantabrian subspecies, I. a. cyreni). Paedomorphic adults are paler in colour than metamorphic ones. Only part of a population is usually paedomorphic, and metamorphosis can follow if the pool dries out. Paedomorphic and metamorphic newts sometimes prefer different prey, but they do interbreed. Overall, paedomorphy appears to be a facultative strategy under particular conditions that are not fully understood. Diet, predators and parasites Alpine newts are diet generalists, taking mainly different invertebrates as prey. Larvae and adults living in the water eat for example plankton. molluscs, larvae of insects such as chironomids, crustaceans such as water fleas, ostracods, or amphipods, and terrestrial insects falling on the surface. Amphibian eggs and larvae, including of their own species, are also eaten. Prey on land includes insects, worms, spiders and woodlice. Predators of adult alpine newts are snakes such as the grass snake, fish such as trout, birds such as herons or ducks, and mammals such as hedgehogs, martens or shrews. Under water, large diving beetles (Dytiscus) can prey on newts, while small efts on land may be predated by ground beetles (Carabus). For eggs and larvae, diving beetles, fish, dragonfly larvae, and other newts are the main enemies.Predator pressure can affect the phenotype of developing alpine newts. In an experiment, alpine newt larvae raised in the presence of caged dragonfly larvae took longer to emerge from the larval stage, growing slower and emerging later in the season than newt larvae that did not experience predator presence. They also exhibited traits such as darker coloration, larger body size, a proportionally larger head and tail, and more wary behavior than their predator-free counterparts. Threatened adult newts often take on a defensive position, where they expose the warning colour of their belly by bending backwards or raising their tail and secrete a milky substance. Only trace amounts of the poison tetrodotoxin, abundant in the North American Pacific newts (Taricha), have been found in the alpine newt. They also sometimes produce sounds, whose