Himalayapotamon emphysetum

Klaus, Sebastian & Brandis, Dirk, 2011, Evolution of sperm morphology in potamid freshwater crabs (Crustacea: Brachyura: Potamoidea), Zoological Journal of the Linnean Society 161 (1), pp. 53-63 : 56

HIMALAYAPOTAMON EMPHYSETUM ( FIGS 3C–F , 4B; TABLE 2)

In Himalayapotamon emphysetum the spermatozoa are less spherical than in Parathelphusula panningi (AW/AL = 0.8 ± 0.08, N = 5). The perforate operculum is centrally bulging and is connected to the acrosomal zones beneath by a ‘tongue-and-groove’ structure. The subacrosomal material and the acrosome ray zone are prominent. Basal to the perforatorial chamber, two parallel oriented centrioles can be recognized. Fragments of laterally situated nuclear arms can be identified. Himalayapotamon emphysetum has cleistospermia.

Figures

Figure 3. Transmission electron microscopy (TEM) of potamid spermatozoa. A, B, Parathelphusula panningi. A, longitudinal sagittal view. B, cross section. C–F, Himalayapotamon emphysetum. C, longitudinal sagittal view; the arrowhead indicates the perforate operculum. D, ‘tongue-and-groove’ connection between the operculum and the acrosomal zones beneath. E, overview of cleistospermic spermatophores. F, cross section. Scale bars: 1 Mm, or as indicated. Abbreviations: arrowhead, vestigial ‘tongue & groove connection’; ar, acrosome ray zone; ia, inner acrosomal zone; nu, nucleus; oa, outer acrosomal zone; op, operculum; pc, perforatorial chamber; tg, ‘tongue-and-groove’ connection; sw, spermatophore wall.

Figure 4. Diagrammatic drawings of potamine spermatozoa. A, Parathelphusula panningi (with cleistospermic spermatophore wall). B, Himalayapotamon emphysetum (with cleistospermic spermatophore wall). C, Socotrapotamon socotrense. Scale bars: 1 Mm.