Cinetomorpha, Simon, 1892

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 : 6

Cinetomorpha sp. (Iguazú)

SPERM TRANSFER FORM ( figs. 3 , 4 ): Large, cone-shaped synspermia (,25 Mm) consisting of four fused spermatozoa ( fig. 3 );

irregular membranes located in the periphery ( fig. 4 A–C). Cytoplasm in sperm conjugate heterogeneous; some dense granules and lamellae occur ( fig. 4 A–C, G). Nuclei incompletely coiled and helically contorted, chromatin irregularly condensed ( fig. 4D, E ). Axonemes hardly visible ( fig. 4F ) due a low electron density compared to the nonhomogeneous cytoplasm. A thin (, 80 nm) secretion sheath, developed in the deferent ducts, surrounds each sperm conjugate ( fig. 4G ).

SPERMATOZOA ( fig. 4 ): Acrosomal complex: AV cylindrical and small (,4.9 Mm); narrow subacrosomal space for the most part, slightly widening posteriorly ( fig. 4E, 4E inset). AF thin, originates from narrow subacrosomal space in anterior AV and extends into a nuclear canal, but clearly ends before axonemal base. Nucleus: prcN elongated (,66.8 Mm) ( fig. 4 A–C), helically contorted, and with a conspicuous, irregular chromatin-condensation pattern. The small implantation fossa contains only centrioles ( fig. 4G ); peN absent. NC empty for the most part in mid and late spermatids and no longer visible in mature sperm. Axoneme: 9+3 microtubular pattern.

NOTES ON SPERMIOGENESIS ( fig. 5 ): Within the testis all stages of spermiogenesis are present. Germ cells of the same developmental stage in conjunction within cyst. The acrosomal vacuole of early spermatids irregularly electron dense, resulting in spotted appearance ( fig. 5A ). It is separated from the anterior pole of the nucleus by a small electron-dense plate. The two centrioles migrate toward posterior pole, where they arrange in a tandem position ( fig. 5B ). Chromatin starts to condense only in a small portion near the nuclear canal that contains the acrosomal filament ( fig. 5C, D ) while the so-called manchette of microtubules (i.e., a ring or ruffle of microtubules) surrounds the entire nuclear material ( fig. 5C, D ). Further development includes elongation of the nucleus. The chromatin condenses irregularly and appears “folded” ( fig. 5E ) with a typical “looped” appearance in cross section ( fig. 5E, H ). Although the axoneme has the typical 9+3 microtubular pattern ( fig. 5F ), the central tubuli are very short, thus the main part of the axoneme shows 9+0 microtubular pattern ( fig. 5G ). While spermatids start to fuse at the end of spermiogenesis, the manchette of microtubules disintegrates ( fig. 5H ).

Figures

Fig. 3. Surface reconstruction of sperm transfer form of Cinetomorpha sp. (Iguazú), illustrating the shape and arrangement of all four fused sperm, as well as the arrangement of an individual sperm. Note the helically contorted nucleus. The axoneme is not shown in this surface reconstruction.

Fig. 4. Characteristics of synspermia of Cinetomorpha sp. (Iguazú). A: One entire sperm conjugate is rather large (approx. 25 Mm). B, C: The nuclei of the four fused sperm are helically contorted, indicated by curls of the latter which are visible in cross sections. D: The chromatin condenses irregularly, resulting in a very specific chromatin-condensation pattern. E: The AV is conical with a widened subacrosomal space near the anterior pole of the nucleus; it appears spoonlike in cross sections (inset). F: The IF is very small, comprising only the two centrioles. G: The Ax, although hardly visible originates from the distal centriole. Note, a peN is not developed.

Fig. 5. Characteristics of spermiogenesis of Cinetomorpha sp. (Iguazú). A: Early spermatids are characterized by small AV that appears spotted. B: The two centrioles arrange in a tandem position and migrate toward the posterior pole of the nucleus initiating the formation of the implantation fossa. C: The chromatin condensation is restricted to a small portion of the nucleus that is often associated with the nuclear canal. D: The NC is located in the periphery of the developing nucleus and contains the AF. E: During further spermatid development, the nucleus enormously elongates and the peculiar chromatincondensation pattern is formed. Note, the nuclear canal is empty for the most part in these spermatids. F: The Ax that originates from the distal centriole extends into the flagellar tunnel. G: Although the axoneme possesses the typical 9+3 microtubular pattern, the central tubules are very short and missing for the most part. H: While four spermatids fuse entirely, the manchette of microtubules disintegrates. Numerous constrictions of the membrane of the syncytium border the early sperm conjugate.