Reproduction by an animal that is still in the larval or pre-adult form. Paedogenesis is a form of neoteny and is particularly marked in the axolotl, a larval form of the salamander, which retains its larval features owing to a lack of thyroid activity as an adaptation to life in an environment deficient in iodine, which is necessary for thyroid function. However, despite this it can breed, producing individuals like itself. If the thyroid hormone thyroxine is given, metamorphosis occurs.