SPERM STRUCTURE OF TRICHOPTERA .2. THE AFLAGELLATED SPERMATOZOA OF HYDROPTILA, ORTHOTRICHIA AND STACTOBIA (HYDROPTILIDAE)

Sperm structure in the caddis-fly family, Hydroptilidae, was examined in order to gain information on the phylogenetic relationships of Tric hoptera. Spermatozoa from 6 species of the genera Hydroptila, Orthotri chia, and Stactobia were immotile and aflagellate, and had large nucle i surrounded by a scant cytoplasm. The cytoplasm contained 2 orthogona lly oriented centrioles and some mitochondria, but no microtubules. Sp ermatogenesis of H. aegyptia was also investigated; spermatocytes I an d early spermatids possessed multiple synaptonemal complexes. Sperm st ructure suggests that Hydroptilidae have followed an independent evolu tionary trend within Trichoptera.