Inachoididae, , Hymenosomatoidea, and Dorippoidea, 1851

GUINOT, DANIÈLE, TAVARES, MARCOS & CASTRO, PETER, 2013, Significance of the sexual openings and supplementary structures on the phylogeny of brachyuran crabs (Crustacea, Decapoda, Brachyura), with new nomina for higher-ranked podotreme taxa, Zootaxa 3665 (1), pp. 1-414 : 127

Family Inachoididae

The male gonopore is coxal and occupies a posteriormost location in relation to sternite 8 ( Fig. 50C, E ). Its large opening is situated at the extremity of the coxo-sternal condyle in Stenorhynchus ( Fig. 31D ). But, as an example of the difficulty in determining the borderline between the strictly condylar and coxal perforations, the gonopore is apparently partially condylar, partially coxal in other inachoidids such as Leurocyclus Rathbun, 1897 ( Fig. 31C ), Paulita , Paradasygyius , Collodes Stimpson, 1860 , and Anasimus (see Modalities of penis protection: Condylar protection). The inachoidid penis is cylindrical, rather short, and ends in a small, narrow papilla. The penis is, however, rather long and lodged in a shallow groove in large adults of Leurocyclus tuberculosus (see Guinot 1984b). The trend to a coxo-sternal condition occurs in Inachoididae with multistate characters as a result of sternal modifications that protect the penis (see Coxo-sternal condition).

Figures

FIGURE 31. A–D. Condylar protection: penis within P5 coxo-sternal condyle. A, Orithyia sinica (Linnaeus, 1771) (Orithyiidae), male 80.0 × 74.0 mm, North China Sea (MNHN-B11612); B, Sayamia germaini (Rathbun, 1902) (Parathelphusidae), male 35.9 × 44.0 mm, holotype of Potamon (Parathelphusa) germaini, Vietnam (MNHN-B5162): penis emerging from extremity of long condyle; C, Leurocyclus tuberculosus (H. Milne Edwards & Lucas, 1842) (Inachoididae), male 33.6 × 36.8 mm, Urugay (MNHN-B9366); D, Stenorhynchus lanceolatus (Brullé, 1837) (Inachoididae), male 34.0 × 16.0 mm, West Africa (MNHN-B21437). E. Non-condylar protection in Dilocarcinus pagei pagei Stimpson, 1861 (Trichodactylidae), male 40.0 × 50.0 mm, Bolivia (MNHN-B12813): penis, with thick sheath, emerging from oblique superior border of condyle. F. Vestigial pleopods on male abdominal somite 5 of Orithyia sinica, same data as in A. a5, a6, abdominal somites 5, 6; c, coxo-sternal condyle; cx5, coxa of P5; e7, episternite 7; G1, first gonopod; I, prominence of sternite 8; m.l., median line; p, penis; pa, papilla; t, sclerotised sheath; te, telson, v, vestigial pleopod; 6–8, thoracic sternites 6–8; 7/8, thoracic sternal suture 7/8. Scale bars: 5 mm (A, F); 1 mm (partial enlargement of A).

FIGURE 50. A–G. Thoracic sternum (A, C, E, G) and ventral surface of abdomen (B, D, F) of Inachidae (A, B), Inachoididae (C–F), and Majidae (G). A, B, Inachus dorsettensis (Pennant, 1777), male 20.0 × 18.0 mm, France, Saint Martin de Ré (MNHN-B17337); C, D, Collodes leptocheles Rathbun, 1894, male 17.5 × 13.2 mm, Gulf of Mexico (MNHN-B14055); E, F, Pyromaia tuberculata (Lockington, 1877), male 17.0 × 12.2 mm, Baja California (MNHN-B9290); G, Prismatopus harmandi (Bouvier, 1906), male 46.0 × 24.5 mm, holotype, vicinity of Tokyo (MNHN-B22330). H. Palicus caronii (Roux, 1828), male 6.0 × 7.0 mm, eastern Atlantic (MNHN-B16335): ventral surface of abdomen with long socket on somite 6. b, press-button.