Evolutionary Morphology Of The Primary Male Reproductive System And Spermatozoa Of Goblin Spiders (Oonopidae; Araneae) Author Lipke, Elisabeth Author Michalik, Peter text Bulletin of the American Museum of Natural History 2015 2015-09-24 2015 396 1 72 http://www.bioone.org/doi/10.1206/906.1 journal article 7643 10.1206/906.1 15ad630f-eff2-451d-a5f8-22731ff53851 0003-0090 4612269 Silhouettella loricatula ( Roewer, 1942 ) SPERM TRANSFER FORM ( fig. 37 ): Large, cone-shaped synspermia comprising four sperm. The cytoplasm of the syncytium is heterogeneous and numerous electron-dense plates and droplets, as well as electron-lucent gaps occur ( fig. 37A, B ). The most obvious characteristic is the distinct, irregular chromatin-condensation pattern ( fig. 37B, C ). Numerous platelike membrane stacks are visible in the periphery of the sperm conjugate ( fig. 37D ). A thin homogeneous secretion sheath (, 100 nm ) surrounds each sperm conjugate ( fig. 37A, B, D ). SPERMATOZOA ( fig. 37 ): Acrosomal complex: AV cylindrical. AF originates from the subacrosomal space and extends into the nuclear canal. Nucleus: prcN elongated, characterized by a conspicuous irregular chromatin-condensation pattern ( fig. 37 A– C) and a very small implantation fossa that contains only the two centrioles ( fig. 37B ). peN not visible in mature sperm; NC located in the periphery ( fig. 37C ), but empty for the most part ( fig. 37C ). Axoneme: 9+3 microtubular pattern. NOTES ON SPERMIOGENESIS ( fig. 38 ): The anterior portion of the prcN is deeply indented and surrounds the AV ( fig. 38A, B ) in addition to a little electron-dense material ( fig. 38B ). Besides the AF the subacrosomal space contains some granular material ( fig. 38B ). The chromatin starts condensation around the nuclear canal ( fig. 38C, D ) before the characteristic chromatin-condensation pattern is formed ( fig. 38 F ). While the nucleus elongates and the chromatin starts to condense, a small dropletlike elongation of the nucleus is formed ( fig. 38E ). This peN probably disintegrates in further development. The implantation fossa is very small and contains only the two centrioles ( fig. 38F ). Neither the centrioles nor the axoneme ( fig. 38F inset) are surrounded by electron-dense material.