Tinadysderina otonga Platnick, Berniker and

Bonaldo, 2013

SPERM TRANSFER FORM (fig. 40): Large (,12 Mm), disclike synspermia (fig. 40A, B) comprising four spermatozoa. Sperm conjugates are flattened, disclike and resemble a dumbbell in cross sections (fig. 40A, B). All sperm conjugates show numerous bacteria occupying the nuclei (fig. 40, D, E). Infected sperm are already visible in the testis, where the spermatid development is likely influenced by means of, e.g., a partially deficient chromatin condensation (fig. 40E inset). A thin, homogeneous secretion sheath (, 80 nm) surrounds the sperm conjugates (fig. 40 F).

SPERMATOZOA (fig. 40): Acrosomal complex: AV conical, thus widened posteriorly (fig. 40C), possessing a narrow subacrosomal space (fig. 40C). AF originates from the subacrosomal space and extends into the nuclear canal, but clearly ends before the base of the Ax. Nucleus: prcN elongated, tubelike with deep implantation fossa that contains numerous mitochondria (fig. 40E), as well as electron-dense secretions. peN long, oval shaped. NC located in the periphery, empty for the most part (fig. 40D). Axoneme: 9+3 microtubular pattern.

NOTES ON SPERMIOGENESIS (fig. 41): Within the testis, all stages of spermiogenesis are visible. Spermatids develop in large cysts. Early spermatids are characterized by, e.g., a large, oval nucleus, and a developing acrosomal complex (fig. 41A, B). Besides the AF the subacrosomal space possesses little electron-dense material (fig. 41B). The nucleus of early spermatids is slightly indented at its anterior pole (fig. 41B). At its posterior pole, a large implantation fossa, containing numerous small mitochondria, is formed (fig. 41C). Further spermatid development includes chromatin condensation, which appears fibrillar in mid spermatids (fig. 41C). As a consequence, the nucleus elongates extremely and involves certain shape changes, finally resulting in a tubelike appearance. The nucleus is always surrounded by a manchette of microtubules (fig. 41D), which disintegrates after sperm conjugation. Additional microtubules located near other cell components are visible in all developmental stages (fig. 41E). The implantation fossa contains little electron-dense secretions, in addition to numerous mitochondria. The two centrioles are arranged in tandem position in late spermatids (41F). At the end of spermiogenesis four spermatids fuse (fig. 41G). These large, early sperm conjugates are characterized by a large, electron-lucent cytoplasm in the center (fig. 41G), and numerous membranes, as well as Golgi derivatives (fig. 41G). The cell membrane of the syncytium is irregularly folded in the periphery (fig. 41G). Further development includes condensation of cytoplasm.