Spermatozoa and sperm packages of the European troglophylous scorpion Belisarius xambeui Simon, 1879 (Troglotayosicidae, Scorpiones).
Studies on the sperm morphology in scorpions are rare, but the existing investigations already revealed a remarkable interfamiliar diversity. The present study reports for the first time on the spermatozoa and sperm packages of a representative of the family Troglotayosicidae, the troglophylous species Belisarius xambeui. The spermatozoa are characterized by (1) a thread-like nucleus, which is slightly bent anteriorly; (2) an asymmetrical cap-like acrosomal vacuole, which encloses the anterior tip of the nucleus; an acrosomal filament is absent; (3) an axoneme with a 9+0 microtubular pattern; (4) a midpiece consisting of elongated mitochondria coiling around the axoneme; the number can vary between 3 and 6 (mostly 4). At the end of spermiogenesis, the spermatozoa aggregate in order to form oval-shaped sperm packages in which all sperm cells show the same orientation. A single package consists of approximately 150 sperms. A secretion sheath is always absent. The present results might provide new characters for further systematic studies and their phylogenetic implications are briefly discussed.
Vignoli
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Dipartimento di Biologia Evolutiva, Università di Siena, Via A. Moro 2, I-53100 Siena, Italy.
Klann
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AE
Michalik
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P
D000177:Acrosome / Q000648:ultrastructure; D000818:Animals; D054468:Axoneme / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D002965:Classification; D005060:Europe; D005837:Genitalia, Male / Q000166:cytology*; D008297:Male; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010802:Phylogeny; D012098:Reproduction; D012605:Scorpions / Q000145:classification* / Q000166:cytology*; D013094:Spermatozoa / Q000648:ultrastructure*; D014617:Vacuoles / Q000648:ultrastructure