Lyreidus tridentatus De Haan, 1841

Guinot, Danièle & Quenette, Gwenaël, 2005, The spermatheca in podotreme crabs (Crustacea, Decapoda, Brachyura, Podotremata) and its phylogenetic implications, Zoosystema 27 (2), pp. 267-342 : 314

Lyreidus tridentatus De Haan, 1841

Female, 17 mm wide, Philippines, MUSOR- STOM 2, stn 30 (MNHN).

The complete sternite 7 is trough-like; it slightly widens anteriorly and becomes deeper to form a depression ( Guinot 1993b: fig. 4; Hartnoll 1979: 76, 80, figs 1-3). The two small spermathecae face each other on opposite sides of this depression and are separated by the vertical median wall, marked externally by the median line ( Fig. 24A ). “A rather indistinct suture crosses it [median line] to link the two openings: this is where the endosternites 7/8 fuse with the median apodeme and the seventh sternite” ( Hartnoll 1979: 77, 78). Each spermathecal aperture is occluded by a membranous area and opens close to the female gonopore on P3 coxa. Because of the distortion of the posterior axial skeleton, “it is possible for the spermathecae to lie in endosternites 7/8, yet at the same time to open anteriorly well away from the sternal suture 7/8” ( Hartnoll 1979: 78).

Figures

FIG. 24. — Posterior part of thoracic sternum in four Raninoidea; A, Lyreidus tridentatus De Haan, 1841 (Lyreidinae); B, Ranina ranina (Linnaeus, 1758) (Ranininae); C, Cosmonotus grayii White, 1847 (Notopodinae); D, Symethis corallica Davie, 1989 (Symethinae). Abbreviations: ccx3-ccx5, articular condyles of P3-P5; g, female gonopore; l.m., median line; pr5, projection from sternite 5 for abdominal maintaining; s, spermatheca; 6-8, thoracic sternites 6-8. Scale bars: A, C, D, 2.5 mm; B, 1 cm.