Opopaea apicalis, Simon, 1893

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 : 43-45

Opopaea apicalis

SPERM TRANSFER FORM ( fig. 25 ): Large sperm transfer forms (.25 Mm),

composed of only a chromatin thread that is embedded in an electron-dense matrix and surrounded by a thin (, 70 nm) homogeneous secretion sheath ( fig. 25A, B ).

Spermatozoa ( fig. 25 ): Acrosomal complex: AV absent. AF absent. Nucleus: prcN condensed chromatin thread that is tightly screwed ( fig. 25C ). peN absent. NC inapplicable (due to missing AF). Axoneme: absent.

NOTES ON SPERMIOGENESIS ( fig. 25 ): The chromatin is highly condensed and appears threadlike ( fig. 25 C–E). Moreover, the chromatin thread is helically contorted. Some

mitochondria are visible. At the end of spermiogenesis, the manchette of microtubules, which surround the developing nucleus ( fig. 25E ), disintegrates.

Figures

Fig. 25. Characteristics of the sperm transfer form of Opopaea apicalis. A: The STF is only composed of a condensed chromatin thread that is embedded in electron-dense cytoplasm and surrounded by a thin secretion sheath. B: Within the periphery of the STF distinct electron-lucent portions are visible. C: The chromatin thread is highly coiled, as is most obvious in late stages of spermiogenesis. D: The manchette of microtubules surrounds the chromatin thread. E: During the sperm development, the nucleus becomes extremely elongated, as indicated by numerous cross sections that are visible within one cell. Further cell components, such as an acrosomal complex, or an Ax are not developed.