For example, there are two types of respiratory organs, 'rectal gills' and 'caudal gills'. The Anisoptera and Anisozygoptera have the former type, and the Zygoptera has the latter. A larva of Calopteryx cornelia belonging to Zygoptera. A larva of Epiophlebia superstus belonging to Anisotygoptera. A larva of Aeshna nigroflava belonging to Anisoptera.
T here are two types of emergence, i.e. upright type and hanging type.
Coenagrionidae, Platyenemididae, Lestidae, Petaluridae and Gomphidae fall into the former, and Calopterygidae, Epiophlebiidae, Cordulegastridae, Aeshnidae, Corduliidae and Libellulidae into the latter. Asiagomphus pryeri Upright type emergence. Anax nigrofasciatus nigrofasciatus Hanging type emergence. The distance of the movement is various among species. An extreme example is the case of a cosmopolitan species, Pantala flavescens , which crosses the ocean from south to Japan.