Trapezioplax tridentata (A. Milne-Edwards, 1880 )

L., Peter K., Castro, Ng Peter, Rodríguez, Paula A. & Moreno, 2024, Notes on the taxonomy of Frevillea A. Milne-Edwards, 1880 (Crustacea, Brachyura, Goneplacoidea), with the description of a new genus for F. sigsbei A. Milne-Edwards, 1880, Zoosystema 46 (29), pp. 733-748 : 741

Trapezioplax tridentata (A. Milne-Edwards, 1880)

( Fig. 4 )

Frevillea tridentata A. Milne-Edwards, 1880: 10 . — A. Milne-Edwards & Bouvier 1923: 338, fig. 4, pl. 6 fig. 3.

Goneplax tridentata – Rathbun 1918: 29.

Trapezioplax tridentata – Guinot 1969b: 513; 1969c: 713, figs 128, 129, 142, pl. 3, fig. 3; 1971: 1082 [in list]. — Ng et al. 2008: 192 [in list]. — Felder et al. 2009: 1081 [in list]. — Thoma et al. 2009: 555, 559; 2014: 90, 92, 100. — Guinot et al. 2013: 293. — Hermoso-Salazar & Arvizu-Coyotzi 2015: 67 [in list].

HISTORY. — Alphonse Milne-Edwards (1880: 16) described F. tridentata from one female measuring 8.0 × 5.0 mm from Blake ’s station 287 in Barbados, Lesser Antilles, from depths of 7.5-50 fathoms (14-91 m). He did not indicate if he had more specimens or if this specimen was the type. For the species, Rathbun (1918: 29) stated: “type-locality, Barbados, “7½ to 50” fathoms, station 287, Blake; holotype in Paris Mus.” and although she did not examine the specimen, her action constitutes the first valid designation of a name-bearing specimen or lectotype for the species.

Alphonse Milne-Edwards & Bouvier (1923: 338) later reported that they had one male (no measurements given but the pleon was figured: A. Milne-Edwards & Bouvier 1923: fig. 4) and one female, which was the one listed and measured in A. Milne-Edwards (1880). Although in the main text they made no mention of a “type,” their captions for the species (A. Milne-Edwards & Bouvier, 1923: pl. 6, fig. 3) stated that the specimens they figured were both types: “Un Type femelle” (A. Milne-Edwards & Bouvier 1923: pl. 6, fig. 3; present Fig. 4A ) and “Abdomen du type. ♂ ” (A. Milne-Edwards & Bouvier 1923: fig. 4; present Fig. 4B ). This action is confusing because they do not specifically identify one specimen as the “type”. Rathbun (1918) is therefore the only author who selected a valid lectotype. There are no type specimens of F. tridentata in MNHN. There are two specimens in the MCZ: a male (6.9 × 4.3 mm) and a female (8.5 × 4.7 mm), both catalogued as MCZ-IZ-CRU-9170. The labels indicate both specimens are “cotypes,” although the database only lists one specimen as a “ syntype.”

TYPE MATERIAL. — On the basis of the literature, the female measuring 8.5 × 4.7 mm is the lectotype of F. tridentata A. Milne-Edwards, 1880 ( Fig. 4C, D ). This measurement is slightly different from that given in the original paper but easily explained (see discussion for F. barbata ). As noted earlier, the other male specimen reported by A. Milne-Edwards & Bouvier (1923) is regarded as a paralectotype ( Fig. 4E, F ).

MATERIAL EXAMINED. — Lectotype (by inference of holotype by Rathbun 1918: 29, as Goneplax tridentata ; A. Milne-Edwards & Bouvier 1923: 338 as F. tridentata ). Lesser Antilles • ♀ (8.5 × 4.7 mm); station 287, off Barbados; 7.5-50 fathoms (= 16-91 m); 13°11’25”N, 59°38’20”W; coll. USCGS; George S. Blake cruise, 8.III.1879; MCZ-IZ-CRU-9170.

Paralectotype. Lesser Antilles • 1 ♂ (6.9 × 4.3 mm); same data as lectotype; MCZ-IZ-CRU-9170 .

ADDITIONAL MATERIAL. — Atlantic • 1 ♂ (9.8 × 6.0 mm); Tortugas, Florida; 18 fathoms (= 33.0 m); coll. W. L. Schmitt, 1924; MNHN- IU-2022-4066 (= MNHN-B10255) .

GEOGRAPHICAL DISTRIBUTION. — Western Atlantic region: Barbados and Gulf of Mexico.

TAXONOMY

Guinot (1969c) established a new genus, Trapezioplax , for F. tridentata on the basis of non-type specimens she had from the Tortugas in Florida deposited in MNHN (MNHNB10255), but she did not examine the types. Her figures ( Guinot 1969c: fig. 142, pl. 3 fig. 3) were based on the MNHN specimen.

Frevillea tridentata A. Milne-Edwards, 1880 , is the only species in Trapezioplax Guinot, 1969c , and is now in the family Pseudorhombilidae Alcock, 1900 .

Figures

FIG. 4. — Frevillea tridentata A. Milne-Edwards, 1880 (now Trapezioplax tridentata): A-D, lectotype ♀ (8.5 × 4.7 mm) (MCZ-IZ-CRU-9170); E, F, paralectotype ♂ (6.9 × 4.3 mm) (MCZ-IZ-CRU-9170); G, H, right cheliped from either male or female specimen from MCZ (MCZ-IZ-CRU-9170); I-K, ambulatory legs from either MCZ specimen: A, C, E, overall dorsal view; B, pleon; D, F, ventral view of cephalothorax; G, right cheliped (dorsal view); H, right cheliped (ventral view); I, right ambulatory leg; J, K, left ambulatory leg. Credits: A, B, after A. Milne-Edwards & Bouvier (1923: fig. 4; pl. 6 fig. 3); C-K, photographs by Alana Rivera, MCZ.