Sperm structure of Limoniidae and their phylogenetic relationship with Tipulidae (Diptera, Nematocera)

The sperm ultrastructure of a few species of Limoniidae (Limonia nigropunctata; L. nubeculosa; Chionea n. sp.; C. alpina; C. lutescens) wasstudied. The two species of Limonia have a monolayered acrosome with crystallized material, a three-lobed nucleus in cross section, a ring ofcentriole adjunct material and a flagellum which consists of a 9 þ 9 þ 1 axoneme and a single mitochondrial derivative. The central axonemaltubule is provided with 15 protofilaments in its tubular wall, while the accessory tubules have 13 protofilaments and are flanked by the electrondenseintertubular material. The three species of Chionea share a monolayered acrosome, a nucleus with two longitudinal grooves, a centrioleadjunct material which surrounds the centriole and the initial part of the axoneme. The axoneme is of conventional type, with 9 þ 9 þ 2microtubular pattern, with accessory tubules provided with 13 protofilaments and intertubular material. However, in C. lutescens the accessorytubules start with 15 protofilaments and transform into a tubule with 13 protofilaments. These data are discussed in the light of the phylogeneticrelationship between Limoniidae and Tipulidae. For this purpose, the sperm ultrastructure of Nephrotoma appendiculata was also consideredcomparatively.