Larval mites (Acari) have only 6 legs in contrast to the 8 legs present in postlarval stages. In the water mites and velvet mites (Parasitengona), larvae are extremely heteromorphic relative to adults, and can not be identified using this key. Larval oribatids have only 1 tarsal claw per leg regardless of the number present in adults, and thus may also be difficult to key. Larvae of other groups of aquatic mites may be identifiable using this key.