“…Motile flagella in arthropods are restricted to sperm cells (Nielsen, 2001), but some taxa, including Acari (represented in our study by Ixodes ricinus) and Branchiopoda (here represented by Daphnia pulex) have aflagellated sperm (Morrow, 2004). Insects generally retain sperm flagella, but they are structurally unusual in most taxa, for example by including supernumerary microtubules (Dallai et al, 2006;Mencarelli et al, 2008). Also the way of assembly of the sperm flagellum is unusual in at least some insect species (e.g., in Drosophila, where it was studied in detail), because it does not rely on IFT (which is employed in the formation of the immotile sensory cilia only; AvidorReiss et al, 2004;Mencarelli et al, 2008).…”