Garthambrus complanatus (Rathbun, 1906)

Mclay, Colin L., 2009, Revision of the crab genus Garthambrus Ng, 1996, with the description of two new genera and discussion of the status of Tutankhamen Rathbun, 1925 (Crustacea: Brachyura: Parthenopidae), Zootaxa 2122, pp. 1-50 : 13

Garthambrus complanatus (Rathbun, 1906)

( Figs 5 E, F, 10B)

Parthenope (Platylambrus) stellata complanata Rathbun, 1906: 884 .

Parthenope (Platylambrus) stellata complanatus — Serène 1968: 60. Parthenope (Platylambrus) complanata — Garth 1993: 789.

Parthenope complanata — Garth & Davie 1995: 226, fig. 3B.

Garthambrus complanata — Ng 1996: 156, 158. – Ng & Tan 1999: 128, figs 4A–B, 6G–I

Type material. LECTOTYPE: male 17.3 x 12.7 mm ( USNM 29845a), Hawaiian Is, Kauai, Hanamaulu Bay, RV Albatross, stn 4132, 22º01’30”N, 150º21’10”W, 470–570 m, 8 foot Blake beam trawl gear, 1 Aug 1902. PARALECTOTYPE: 1 male ( USNM 29845b) (not examined), same data as lectotype.

Diagnosis. Carapace tuberculate, not spinose, without deep lacunae; supra-orbital region not spinose. Tubercles on protogastric, mesogastric, epibranchial, cardiac regions not fused to form smooth ridges or plates. Frontal projection short, less than one quarter carapace length. Epibranchial margin teeth broad, tips denticulate. Mesobranchial margin with raised, smooth, triangular patch. Sub-orbital spine produced, spine tip extending beyond anterior outer corner of antennal article 2. Posterior sub-branchial region sparsely tuberculate. Cheliped merus, carpus outer margins tuberculate, tubercle tips triangular. P5 merus, carpus, upper margins of propodus tuberculate; merus, carpus, posterior surface of propodus tuberculate; tubercles very small, low. Female unknown.

Distribution. Known only from the Hawaiian Is.

Remarks. One of the diagnostic features of this species is the presence of a smooth triangular patch at the metabranchial margin, which is absent in the other species of Garthambrus . A similar structure is seen in G. allisoni , but the patch is heavily tuberculate and vaguely shaped like an inverted ‘V’ rather than triangular.

Figures

FIGURE 5. Gonopods. Garthambrus poupini (Garth, 1993): A, B, holotype, male 35.5 x 28.0 mm (MNHN B 22424), French Polynesia, Tuamotu Archipelago, Fangataufa (after Garth 1992: figs. 2 d, e) (scale bar not available). — Garthambrus allisoni (Garth, 1993): C, D, holotype, male 23.5 x 17.8 mm (LACM; ex. AHF 645), Easter I. Fracture Zone (after Garth 1992: fig. 5 f) (scale bar = 1 mm). — Garthambrus complanatus (Rathbun, 1906): E, F, lectotype, male 17.3 x 12.7 mm (USNM 29845 a), Hawaiian Is, Kauai (scale bar = 1 mm). A, E, left G 1; B, F, left G 2; C, right G 1; D, right G 2.