Paradysderina yanayacu, Platnick

Lipke, Elisabeth & Michalik, Peter, 2015, Evolutionary Morphology Of The Primary Male Reproductive System And Spermatozoa Of Goblin Spiders (Oonopidae; Araneae), Bulletin of the American Museum of Natural History 2015 (396), pp. 1-72 : 49-50

S caphios yanayacu Platnick and Dupérre´, 2010

SPERM TRANSFER FORM ( fig. 35 ): Synspermia that comprise four sperm. The entire sperm conjugate is rather large and unsheathed. Within the lumen of the proximal deferent ducts, the nuclei of sperm of one sperm conjugate appear still spotted ( fig. 35A, B ), while a distinct vesicular area that is composed of numerous electron-dense vesicles surrounds the main sperm cell components ( fig. 35A, B ). In the distal deferent ducts this vesicular area is homogeneously electron dense ( fig. 35C, D ). The periphery of the sperm conjugate is built by large quantities of granular cytoplasm of the syncytium, which contains numerous mitochondria and vesicles ( fig. 35C ). Only the axonemes coil within the membrane of the syncytium ( fig. 35 D–E).

SPERMATOZOA ( fig. 35 ): Acrosomal complex: AV conical with moderately widened subacrosomal space ( fig. 35F ). AF originates from the subacrosomal space and extends into the nuclear canal but clearly ends before the base of the axoneme. Nucleus: prcN elongat- ed, compact, and tubelike ( fig. 35C ) with a small implantation fossa that comprises only the two centrioles. peN not identifiable. NC located in the periphery, in late spermatids not identifiable. Axoneme: 9+3 microtubular pattern ( fig. 35D, E ).

NOTES ON SPERMIOGENESIS ( fig. 36 ): The periphery of spermatids of all developmental stages is frequently invaginated and folded, resulting in a loose and spongy appearance ( fig. 36A ). Early spermatids are characterized by a large, oval nucleus with already irregularly condensed chromatin ( fig. 36A ). The subacrosomal space of the developing AV is enlarged ( fig. 36B ). The AF extends into the NC ( fig. 36B ) but clearly ends before the end of the axonemal base ( fig. 36B, E inset). The AV is surrounded by electrondense material in mid spermatids ( fig. 36C ). The chromatin condenses irregularly, resulting in a spotted appearance of the nucleus of mid- and late spermatids ( fig. 36D, E ). Conspicuous membrane whorls, as well as electron-dense vesicles are in close association to the nucleus ( fig. 36D ). At the end of spermiogenesis, four spermatids fuse, while the main sperm cell components arrange in the center of the developing sperm conjugate ( fig. 36F ).

Figures

Fig. 35. Characteristics of synspermia of Scaphios yanayacu. A: Within the testis and proximal portion of the deferent ducts, the sperm conjugate is very voluminous, although the sperm cell components are restricted to a small portion that is located in the center of the synsperm. B: Furthermore, the vesicular area that surrounds the sperm cell components appears granular and the chromatin still looks spotty. C: Within the distal portion of the deferent ducts the cytoplasm of synspermia is compressed and numerous mitochondria are visible. D: Finally, the vesicular area is homogeneously electron dense. E: The microtubular pattern of the axoneme is hardly visible due to its electron density. The cytoplasm adjacent to the nuclei appears granular and presumably contains some glycogen. F: The anterior pole of nucleus is slightly indented.

Fig. 36. Characteristics of spermiogenesis of Scaphios yanayacu. A: Early spermatids are characterized by a peculiar chromatin-condensation pattern. B: The acrosomal vacuole of early spermatids possesses an enlarged subacrosomal space. C: In midspermatids the AV is surrounded by electron-dense material. D: Numerous membrane whirls are visible in close association to the elongating nucleus in mid- and late spermatids. E: A multilayered manchette of microtubules surrounds the nucleus for its most part; the AF that runs inside the nuclear canal clearly ends before the axonemal base (inset). F: At the end of spermiogenesis four spermatids fuse completely and arrange in the middle of the voluminous sperm conjugate.