The larval ontogeny of Coryphaeschna perrensi (McLachlan, 1887): Supporting monophyletic groups in Aeshnidae dragonflies (Insecta: Odonata: Anisoptera).

Abstract

The development of the larval external morphology of Coryphaeschna perrensi is reported based primarily on a comparison of successive exuviae of reared specimens, with the second stadium larvae first described separately. Accentuated changes observable throughout successive moltings occur in some structures, such as the head capsule, labium, and anal appendages, allowing for the definition of characters with naturally ordered, polarized, and linear states (transformation series) by ontogenetic evidence. The terminal (less general) and nonterminal (more general) states of the described transformation series correspond by primary homology to the conditions found in larvae of other dragonfly species. Consequently, as the result of a parsimony analysis and subsequently ontogenetic rooting, the disposition of the states of 17 characters in a sample of final-stadium larvae of 23 species, representatives of the six Aeshnidae tribes (21) and Austropetaliidae (2), results in a hierarchical network comprising six distinct taxonomic levels of inclusion of C. perrensi. The levels correspond to Aeshnidae, Aeshninae, Aeshnini (part) + Gynacanthini, Coryphaeschna + Remartinia, Coryphaeschna, and Coryphaeschna except C. adnexa, which are groups previously recognized as monophyletic resulting from analyses considering adult morphology. Immature insect morphology coupled with ontogenetic observation presenting great potential to hypothesize phylogenetic relationships and investigate heterochronic events.