Rochinia gracilipes A. Milne-Edwards, 1875

Lee, Bee Yan, Richer De Forges, Bertrand & Ng, Peter K. L., 2020, Revision of the deep-water spider crab genus, Scyramathia A. Milne-Edwards, 1880, with the description of a new species from the Mediterranean and notes on Rochinia A. Milne-Edwards, 1875, and Anamathia Smith, 1885 (Crustacea, Decapoda, Brachyura, Epialtidae), Zoosystematics and Evolution 96 (2), pp. 537-569 : 537

Rochinia gracilipes A. Milne-Edwards, 1875 Figs 1A-C , 2A-F

Rochinia gracilipes A. Milne-Edwards 1875 [in 1873-1880]: 86 (footnote) (type locality: Cape Corrientes, Argentina); Griffin and Tranter 1986: 174 (list); Rathbun 1925: 210 (key), 218, pl. 229 figs 1-4; Monod 1956: 32 (list), 516-517 (in part); Garth 1958: 282 (list), 283 (list); Manning and Holthuis 1981: 253 (list), 254, 255; Tavares 1991: 160, 161 (list), 164, figs 3A, 5B; De Melo 1996: 266 (key), 268, unnumbered in-text fig.; Tavares and De Melo 2004: 130; Ng and Richer de Forges 2007: 61, 63 (list); Ng et al. 2008: 105 (list); Ng and Richer de Forges 2013: 362, fig. 5A; Pettan 2013: 2 (list), 3 (list), 5 (list), 6 (list), 10 (list), 11 (list), 12, 14, 16, 20, 26, 41, 47, 86 (key), figs 10a, b, 16d, 23a, b; Griffiths et al. 2014: 185, map 8; Pettan and Tavares 2014: 306 (list); Ceccon and De Angeli 2018: 151 (list); Tavares and Santana 2018: 201, 204, 223 (list), figs 2, 9D, 10A, B, 11A, 12A, 13I-J; Spivak et al. 2019: 95, fig. 51.

Rachinia [sic] gracilipes : A. Milne-Edwards 1875 [in 1873-1880]: pl. 18 fig. 1-1d; Lagerberg 1905: 22-24.

Materials examined.

Paralectotypes: 1 ♂ [dry] (20.0 × 15.0 mm, 1 ♀ (10.4 × 8.5 mm) ( MNHN-IU-2000-4460 [= MNHN-B4460]), Cap. Corrientes, coll. A Milne-Edwards. Other material: 3 ovigerous ♀♀ (15.1 × 11.1 mm, 14.9 × 10.8 mm, 14.5 × 10.1 mm), 3 ♀♀ (15.2 × 11.1 mm, 14.1 × 9.7 mm, 12.5 × 9.2 mm) ( ZRC 2019.1634), Mar del Plata Habour, Argentina, 38°02'S, 57°31'30"W, coll. N Farias, 9 October 2014; 1 ovigerous ♀ (16.0 × 11.5 mm) ( USNM 1277591), Mar del Plata, Buenos Aires Province, Argentina, South Atlantic Ocean, coll. M Doella-Jurado, 7 August 1911; 2 ♂ (15.2 × 10.6 mm, 11.9 × 9.8 mm) ( USNM 1150573), Mar del Plata, Buenos Aires, Argentina, South Atlantic Ocean, coll. Franceschi and Lelois, February 1924; 1 ♂ (17.2 × 12.4 mm) ( USNM 1150574), Mar del Plata, Buenos Aires, Argentina, South Atlantic Ocean, coll. M Doella-Jurado, 1914; 1 ♂ (10.5 × 7.1 mm), 1 ovigerous ♀ (14.0 × 10.1 mm) ( USNM 55118), 40°22'S, 60°35'W, 55 m, coll. Hassler Expedition, 1951.

Remarks.

No type specimen was designated when this species was described by A. Milne-Edwards (1875: 86 [footnote]) although various specimens from "la collection du Muséum” (i.e., the Muséum national d’Histoire naturelle ( MNHN), Paris) as well as specimens from Hassler expedition were mentioned. There is also a figure of a male specimen provided in the same paper, but the name was incorrectly spelled as " Rachinia gracilipes " in the caption (see A. Milne-Edwards 1875: pl. 18 fig. 1). The male specimen that is found in the MNHN ( MNHN-IU-2000-4460 [= MNHN-B4460]) matches the figure provided by A. Milne-Edwards (1875: pl. 18 fig. 1-1d). The same male specimen was used by Tavares (1991: figs 3A, 5B) and was considered a syntype by the author. This was, however, not listed by Tavares and Santana (2018) in their study to redefine Rochinia , when they designated another specimen as the lectotype for this species. It was mentioned by Tavares and Santana (2018) that the type material needs clarification and that the male specimen that was illustrated by A. Milne-Edwards (1875: pl. 18, fig. 1-1d) and deposited in the MNHN was clearly not the holotype as had been identified by Rathbun (1925). Rathbun’s (1925) recognition of the “holotype” is incorrect as no type was selected in the original description by A. Milne-Edwards (1875) and all the material must be considered syntypes. Tavares and Santana (2018) designated one male specimen ( MCZ 1950) as the lectotype for this species and five other female specimens as the paralectotypes, all collected from the Hassler expedition. Based on the original description by A. Milne-Edwards (1875: 86) and the figure (A. Milne-Edwards 1875: pl. 18 fig. 1-1d), the specimens from MNHN are also part of the type series. The G1 and G2 of the paralectotype male ( MNHN-IU-2000-4460 [= MNHN-B4460]) is illustrated here (Fig. 2A-F ). The type locality of this species is Cape Corrientes (= Cabo Corrientes), Argentina, and specimens are found in relatively shallow waters (about 55 m depth) (see also Tavares & Santana, 2018: 221).

Rochinia gracilipes was recorded from the coast of Africa near Gabon by Monod (1956). The male specimen figured ( Monod 1956: figs 706-708) was compared with the MNHN type specimen and it does resemble the present concept of R. gracilipes . Monod (1956: 517), however, was not certain of the origin of the specimen and noted that its presence in African waters needs to be confirmed. Monod (1956) 's dubious African record is not included in the synonymy for this species for the time being.

Distribution.

Currently only known from its type locality, Cape Corrientes (= Cabo Corrientes), Mar del Plata, Argentina (A. Milne-Edwards 1875), southeastern Brazilian coast (Spivak et al. 2019), South Shetland Islands (Griffiths et al. 2014); Antarctic Peninsula (De Melo, 1996; Tavares and Melo 2004).

Figures

Figure 1. Rochinia gracilipes A. Milne-Edwards, 1875, paralectotype male [dry] (20.0 x 15.0 mm) (MNHN-IU- 2000 - 4460 [= MNHN-B 4460]), Cap. Corrientes. A. overall dorsal view; B. overall ventral view; C. lateral view of carapace.

Figure 2. A-D. Rochinia gracilipes A. Milne-Edwards, 1875, paralectotype male (20.0 x 15.0 mm) (MNHN-IU- 2000 - 4460 [= MNHN = B 4460]), Cap. Corrientes, left G 1; A. ventral view; B. ventral view of distal portion; C. dorsal view; D. dorsal view of distal portion; E-F. R. gracilipes A. Milne-Edwards, 1875, male (15.2 x 10.6 mm) (USNM 1150573), Argentina, left G 2; E. ventral view of G 2; F. dorsal view of G 2. Scale bars: 1 mm.