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 Orchestina sp. 1 ( Chile ) SPERM TRANSFER FORM ( figs. 26 , 27 ): Long (.80 Mm), tubelike synspermia ( fig. 26 ), comprising two sperm ( fig. 26 ) that are arranged consecutively to each other ( fig. 26 ). A thick electron-dense secretion sheath (, 800 nm ) surrounds the sperm conjugates ( fig. 27 A–D). Sperm cell components are uncoiled ( fig. 26 ) and surrounded by a small amount of conspicuous electron-dense fibrils, mitochondria are present ( fig. 27B ). Fig. 41. Characteristics of spermiogenesis of Tinadysderina otonga . A : The implantation fossa of early spermatids is already filled with a large amount of mitochondria. B : The subacrosomal space is enlarged toward the anterior pole of nucleus. C : The chromatin appears fibrillar in mid spermatids. D : During further development, the chromatin condenses irregularly as indicated by the manchette of microtubules, which illustrates the actual dimensions of the nucleus. E : Little electron-dense material surrounds the microtubules of the axoneme. F : In addition to mitochondria, small electron-dense secretions are located in the IF. G : At the end of spermiogenesis four spermatids fuse to form synspermia. SPERMATOZOA ( fig. 27 ): Acrosomal complex: AV small, cylindrical. AF originates from the subacrosomal space and extend into the nuclear canal. Nucleus: prcN tubelike and elongated (,19.2 Mm) with deep implantation fossa that extends as far as the anterior pole of the nucleus and is filled with a distinct, electron-dense centriolar adjunct ( fig. 27C ). peN absent ( fig. 27E ). NC located in the periphery. Axoneme: short (,19.2 Mm); 9+3 microtubular pattern. NOTES ON SPERMIOGENESIS ( fig. 28 ): Within the testis all stages of spermiogenesis are visible. A small, developing AV is attached to the cell membrane ( fig. 28A , inset) and extends toward the anterior pole of nucleus, from which it is separated by a distinct electron-dense plate ( fig. 28A ). The AF originates from the subacrosomal space. During development of the spermatids the chromatin condenses and appears fibrillar in midspermatids ( fig. 28 B–D). The deep implantation fossa of early and midspermatids is filled with numerous microfilaments ( fig. 28 C, D ) and few electron-dense secretions ( fig. 28C, D ) that form a distinct centriolar adjunct in late spermatids, which completely covers the proximal centriole ( fig. 28 E–G). In the periphery of the developing spermatids numerous looplike constrictions are visible ( fig. 28H inset), resulting in a fringed appearance of the latter ( fig. 28H, I ).