The spermatozoon ofCalocarcinus africanus(Heterotremata, Brachyura, Crustacea): ultrastructural synapomorphies with xanthid sperm
| Autor: | Barrie G. M. Jamieson, B. Richer de Forges, Danièle Guinot |
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| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | Invertebrate Reproduction & Development. 24:189-195 |
| ISSN: | 2157-0272 0792-4259 |
| DOI: | 10.1080/07924259.1993.9672351 |
| Popis: | Summary Features of the spermatozoon of Calocarcinus africanus which are general for heterotremes and endorse its inclusion in the Heterotremata are: extension of the subacrosomal chamber almost to the anterior apex of the sperm, presence of an acrosome ray zone, and presence of a thickened ring where the capsule surrounds the base of the subacrosomal chamber. A feature shared with “higher” heterotremes is the restriction of cytoplasm to the periacrosomal region, the arms being nuclear only, in contrast with invasion of their chromatin with cytoplasm and microtubules in majids; and loss of a posterior median process, containing chromatin, which is present in majids as in raninids and homolids. The relationship of Calocarcinus with xanthids is unequivocally supported by (1) presence of a posterior circumperforatorial zone, the xanthid ring; (2) the precise form of the acrosome ray zone which is wide anteriorly and sends a long slender extension posteriorly to meet the ring; (3) the irregular external margi... |
| Databáze: | OpenAIRE |
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