Open AccessDie Spermapumpen der Strepsiptera und Antliophora (Hexapoda)
Author(s) -
Hünefeld F.,
Beutel R. G.
Publication year - 2005
Publication title -
journal of zoological systematics and evolutionary research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.769
H-Index - 50
eISSN - 1439-0469
pISSN - 0947-5745
DOI - 10.1111/j.1439-0469.2005.00327.x
Subject(s) - biology , autapomorphy , anatomy , sperm , hexapoda , zoology , phylogenetics , taxonomy (biology) , genetics , gene
Male genital structures of representatives of Strepsiptera, Siphonaptera and Diptera are described in detail, with special emphasis on sperm pumps. The parts involved in the apparatus are evaluated with respect to their homology. Functional interpretations are presented based on the morphological observations. The phylogenetic significance of characters related to the male genital apparatus is discussed. The sperm pumps differ strongly in Strepsiptera and Antliophora ( s.s. ) and are not homologous. The strepsipteran type, which lacks any sclerotized parts, has evolved independently. Autapomophies of the male genital apparatus are the compact testes, the large balloon‐shaped vesicula seminalis, the strongly developed musculature of the proximal ductus ejaculatorius, the strongly simplified copulatory organ, the unusual muscles of segments VIII and IX, and the complete absence of accessory glands. The median fusion and almost globular shape of the vesicula are potential autapomorphies of Corioxenidae. The absence of the furrow separating the testes from the vesicula seminalis is a derived condition found in Xenos and Myrmecolax . A sperm pump is absent in Boreus (Mecoptera) and Culicomorpha and the functionally relevant parts and their arrangement differ strongly in Siphonaptera, Pistillifera and Diptera (excl. Culicomorpha). The presence of a functional and homologous pumping apparatus does not belong to the groundplan of Antliophora, which implies that this alleged autapomorphy of the clade is invalid. A sperm pump belongs to the groundplan of Diptera and was secondarily reduced in Culicomorpha, many representatives of Bibionomorpha, and in Diopsidae. It was very likely primarily absent in Mecoptera. However, the precise reconstruction of the groundplan depends on the position of Nannochoristidae within Mecoptera and on the possible affinities of Siphonaptera and Boreidae. Sperm pumps should be considered as a functional term and not be used as a character for phylogenetic reconstruction, unless specific similarities are included in the character definition.