Gecarcinus digueti Bouvier, 1895

Ng, Ngan Kee, Rodríguez Moreno, Paula A., Naruse, Tohru, Guinot, Danièle & Mollaret, Noémy, 2019, Annotated type-catalogue of Brachyura (Crustacea, Decapoda) of the Muséum national d’Histoire naturelle, Paris. Part II. Gecarcinidae and Grapsidae (Thoracotremata, Grapsoidea), with an Appendix of pre- 1900 collectors, Zoosystema 41 (7), pp. 91-130 : 98-99

Gecarcinus digueti Bouvier, 1895

( Fig. 2D )

Gecarcinus Digueti Bouvier, 1895: 8 ; 1898: 372.

CURRENT TAXONOMIC STATUS. — Junior subjective synonym of Johngarthia planata ( Stimpson, 1860) (see Bouvier 1898: 372).

HOLOTYPE (by monotypy, see Rathbun 1899). — MNHN-IU-2000-10951 (= MNHN-B10951 ), ♂ 46.3 × 69.0 mm, Baja California, coll. M. Diguet, E.-L. Bouvier det. — Original label: “ Gecarcinus planatus Stimpson, Basse-Californie, M. Diguet, (1898) , E.-L. Bouvier det.”.

PRESERVATION. — Dry.

REMARKS

The species is known based on a short description by Bouvier (1895: 8) for a unique specimen brought by Diguet from Baja California in Mexico in 1894 (“ Basse-Californie ” in Bouvier 1895: 6). This specimen MNHN-IU-2000-10951 (= MNHN-B10951), a male specimen, dry, 67.0 mm cw according to Bouvier (1898: 372), can be considered the holotype by monotypy of Gecarcinus digueti . Rathbun (1899: 73), who wrote “The type and only specimen hitherto collected is from Lower California and is in the Paris Museum”, provided several measurements of body parts of this specimen, notably for the carapace 46.3 × 69.0 mm (measurements presently verified). The species was redescribed by Bouvier (1898: 372) with more detail (but not figured) based on another specimen collected in 1897 by Diguet in the same region, a male MNHN-IU-2016-8892 (= MNHN-B16029), now preserved in alcohol. This second specimen was not taken into account by Rathbun (1899: 73; 1918: 359, under Gecarcinus planatus Stimpson, 1860 ).

Perger et al. (2011: 58, 59), based on information from the MNHN, agreed that the male MNHN-IU-2000-10951 (= MNHN-B10951) was most likely the holotype of Gecarcinus digueti , being “the only specimen in the MNHN concordant with the type specimen of G. digueti described by Bouvier (1895) and subsequently reported by Rathbun (1899) […]. Rathbun (1899) recognised G. digueti as a distinct species, recording it from María Cleofa Island [i.e., Cleofas Island] in the Gulf of California, and apparently examined the type in the Paris Museum which she stated was a male measuring 69.0 by 46.3 mm […]. On the basis of the available data, this MNHN specimen is almost certainly the holotype of G. digueti Bouvier, 1895 .”

Diguet is known for his trips in Mexico (see Appendix); “ Basse-Californie ” of Bouvier (1895; 1898) and on the MNHN label corresponds to Baja California, Mexico (not Southern California, United States).

Gecarcinus digueti was synonymised with G. planatus Stimpson, 1860 by Bouvier (1898: 372), Rathbun (1918: 359), Türkay (1970: 346, as Gecarcinus ( Johngarthia )), and by Perger et al. (2011: 59, as Johngarthia ) who concluded: “The presumptive holotype of G. digueti has all the diagnostic characters which we here identify with J. planatus and we are confident they are conspecific.”

Figures

FIG. 2. — A, Cardisoma urvillei H. Milne Edwards, 1853, MNHN-IU-2000-3735 (= MNHN-B3735),lectotype, ♂; B, Discoplax gracilipes Ng & Guinot, 2001, MNHN- IU-2014-11214 (= MNHN-B26950),paratype,♀; C, Discoplax longipes A.Milne-Edwards,1867,MNHN-IU-2000-3763 (= MNHN-B3763),lectotype,♂; D, Gecarcinus digueti Bouvier,1895,MNHN-IU-2000-10951 (= MNHN-B10951),holotype,♂; E, Gecarcinus lagostoma H. Milne Edwards,1837,MNHN-IU-2000-3750 (= MNHN- B3750), lectotype, ♂; F, Gecarcinus lateralis Fréminville in Guérin-Méneville, 1832, MNHN-IU-2000-3758 (= MNHN-B3758), neotype, ♂; G, Gecarcinus nobilii Perger & Wall, 2014, MNHN-IU-2014-11211 (= MNHN-B12314), paratype, ♀; H, Pelocarcinus cailloti A. Milne-Edwards, 1890, MNHN-IU-2000-3751 (= MNHN- B3751), holotype, ♂. Scale bars: A, E, 5 cm; B-D, F-H, 2 cm.