refers to a caudate that does not normally metamorphose. In other words, it looks like a tadpole its whole life, even when it is sexually mature. Some salamanders have both neotenic and 'normal' forms. Neotenics can often be forced to morph by simulating drought conditions and/or adding iodine to the water to stimulate production of thyroxine. Neotenics are generally much larger than terrestrial salamanders; a neotenic Ambystoma tigrinum can be 30 inches long, while the terrestrial form rarely exceeds 10 inches. See also "paedogenesis."