Morphological diversity of the skeletal structures of fleas (Siphonaptera). Part 1: the general characteristic and features of the head

Analysis of a considerable amount of data on the anatomy of 14 structures of the head capsule in 96 genera of fleas (over 90% of the genera in the world fauna) shows that different flea taxa can be described based on 32 universal and specific characters, whose 135 states reflect the entire known diversity of the flea head morphology. Of them, 17 characters can be formulated based on universal terms applicable to any structure. Elementary characters can reflect phylogenetic affinity only in association with specific characters; these 15 characters are formulated based on specific features of the flea morphology and describe interrelations of the skeletal structures (or microstructures of a particular formation). The concept of a “structural type” is used for multi-aspect characteristics of different character states of some structures. Homoplasies at various levels comprise more than half (53%) of all the character states in the head structure. The character states reflecting the phylogenetic closeness of taxa make up about 22%. © 2015, Pleiades Publishing, Inc.