Escaphiella ramirezi Platnick and Dupérre´, 2009

SPERM TRANSFER FORM (figs. 6, 7): Very large, elongated synspermia (,70 Mm) that

comprise four spermatozoa (fig. 7A, B). Overall shape of this sperm conjugate bonelike (fig. 6). A slender vesicular area surrounds all sperm-cell components (fig. 7B, D, E). The acrosomal vacuoles, which represent the anterior pole of sperm are located in the middle of the sperm conjugate (fig. 6, arrow), Two sperm arranged opposed to each other (two sperm coil clockwise, the remaining two counter clockwise). Cytoplasm of the sperm conjugate electron lucent. Numerous, circular Golgi derivatives are present, mainly located in the periphery of the sperm conjugate (fig. 7 A–C) and sometimes associated with the membrane of the syncytium (fig. 7C). Synspermia surrounded by a thin (, 50 nm) secretion sheath (fig. 8B, C) that is produced in the deferent ducts.

SPERMATOZOA (fig. 7): Acrosomal complex: AV very short (,1.9 Mm), cylindrical, narrow subacrosomal space (fig. 8D). AF originates from the subacrosomal space of the acrosomal vacuole and extends into the nuclear canal; ends in the region of the axonemal base (fig. 7E); extremely elongated (,125.2 Mm) and for most part remarkably large, resembling the most prominent cell component (fig. 7B). Nucleus: prcN extremely elongated (,126 Mm) (fig. 6). Most pro- minent part of the prcN is the nuclear canal that contains the massive acrosomal filament (see above, figs. 6, 7 B–E). Condensed chromatin is restricted to a small portion around the latter (fig. 7 B–E). Implantation fossa extremely small, containing only the centrioles (fig. 7E). peN very short (,1.3 Mm) and thin, flag shaped (figs. 6, 7E). Axoneme: short (,58.4 Mm), 9+3 microtubular pattern (fig. 7B, D); centrioles arranged rectangularly, proximal centriole very short.

NOTES ON SPERMIOGENESIS (fig. 8): Cysts of developing sperm (mainly early and midspermatids) present within the testis. Early spermatids characterized by a small vesiclelike AV that is attached to the cell membrane (fig. 8A). Originating from the subacrosomal space, AF comprises only a few filaments in the AV as indicated by cross sections (fig. 8 A). In contrast, it expands to a massive rod composed of numerous filaments (fig. 8 B–D) within NC. Nucleus is surrounded by a manchette of microtubules and chromatin appears fibrillar in early and midspermatids (fig. 8B, C). While nucleus elongates, condensed chromatin constricted to a small portion (fig. 8D). Axoneme originates from the distal centriole (fig. 8E). Occasionally, small electron-dense spots are present in the periphery, likely inside NC, associated with AF. At the end of spermiogenesis, several spermatids start to fuse, resulting in voluminous sperm conjugates that remain connected to each other via cellular bridges (fig. 8F). A loose, electron-dense network of fused vesicles, representing an early stage vesicular area, surrounds all main sperm cell components (fig. 8F inset).