Collodes leptocheles Rathbun, 1894

Alves-Júnior, Flavio De Almeida, Lucatelli, Débora, Santana, William & Souza-Filho, Jesser Fidelis De, 2019, First record of two rare spider crabs (Crustacea: Decapoda: Brachyura: Majoidea) from Brazil, Zootaxa 4688 (1), pp. 111-118 : 115

Collodes leptocheles Rathbun, 1894

( Fig. 4 )

Collodes leptocheles Rathbun, 1894: 53—1900 : 508; 1925: 117, fig. 42, pl. 38, figs. 5–6.— Pequegnat 1970: 181 — Powers 1977: 44 — Abele & Kim 1986: 38 — Boschi 2000: 75 — McLaughlin et al. 2005: 251, 311— Ng et al. 2008: 115 (list)— Felder et al. 2009: 1076 — Santana & Tavares 2017: 1147 (comparative material).

Material examined. 2 females, cl: 42 & 45 mm, cw: 12 & 13 mm ( MOUFPE 19233 ), R/ V Seaward Johnson, Potiguar Basin, Rio Grande do Norte, Station #MT–52, 04°44’S, 036°25’W, 23 May 2011, otter trawl, 180 m, gravel bottom, temperature 28.8°C, salinity 36.6 .

Geographic distribution. Western Atlantic: Gulf of Mexico (Florida – type locality – Louisiana and southeast of Caribbean Sea) ( Rathbun 1894; Felder et al. 2009) and Brazil (Rio Grande do Norte) (present study).

Occurring between 91 and 384 m depth ( Rathbun 1894; Pequegnat 1970; Abele & Kim 1986; Felder et al. 2009).

Remarks. Collodes Stimpson, 1860 , is an endemic, amphi-American genus inhabiting shallow waters down to around 700 m. The genus currently comprises of 16 species, five of which are found in Brazilian waters: Collodes armatus Rathbun, 1898 ; C. inermis A. Milne-Edwards, 1878 ; C. rostratus A. Milne-Edwards, 1879 ; C. trispinosus Stimpson, 1871 ; and C. tuerkayi Santana & Tavares, 2017 (see Santana & Tavares 2017).

The present specimens fit well with the original description provided by Rathbun (1894), but presented some variations, highlighted in bold:

Carapace pyriform, longer than wide, dorsal surface densely covered with tubercles ( Fig. 4A ); branchial, cardiac, intestinal spines absent ( Fig 4A ). Rostrum short, bifurcated, divided by U-shaped notch into two blunt teeth ( Fig. 4C ). Antenna distinctly exceeding rostral length, third article slightly shorter. Supraorbital spine absent; postorbital tooth broad and long, as long as the eyestalk, directed laterally, tip slightly curved anteriorly ( Fig. 4C ). Antennular fossae elongated, septum long formed by a strong spine, which does not exceed the septum area ( Fig. 4D ); antenullar flagellum surpassing the rostrum tip, with first and second antennal articles fused to epistome. Epistome slightly wider than long ( Fig. 4D ); epistomial spine separated by small gap from inter-antennular septum ( Fig. 4D ). Mouth subrectangular; pterygostomial spine with few subequal tubercles. Third maxilliped with long exopod, reaching halfway along length of merus, dorsal face with subequals tubercles; ischium longer than wide; merus longer than half of ischium; palp cylindrical, longer than merus, with rows of setae. Hepatic region well marked, convex. Chelipeds subcylindrical in both sexes, slender, fingers as long as palm ( Fig. 4F ); merus, ischium with few tubercles; propodus, carpus, dactylus smooth with long setae. Pereopods 2–5 (ambulatory legs 1–4) slender, slightly granulated, setose; P2, P3 longest when compared with the P4, P5 ( Fig. 4A, B ); merus, carpus, propodus, dactylus covered with small tubercles; dactylus broadly curved ( Fig. 4A ). Pleotelson subtriangular, rounded distally ( Fig. 4E ). Pleonal somites 1–4 free, somites 5, 6 and telson fused ( Fig. 4B ). Females present a prominent tubercle in the midline of fifth abdominal somite ( Fig. 4B ) and one prominent spine on first ( Fig. 4A ).

Collodes leptocheles is closely related to C. robustus Smith, 1883 (distributed from Massachusetts to Florida on the US east coast, the Gulf of Mexico and the southeastern Caribbean Sea), but is distinguished from it by the fifth pleonal somite having a strong spine in males and a prominent tubercle in the midline in females ( Fig. 4B ) (versus fifth abdominal somite without spines in males and with small, evenly distributed tubercles in females C. robustus ). Collodes leptocheles was previously known from the Gulf of Mexico ( Felder et al. 2009) and is here recorded for the first time from far further south (about 6,800 km) off the northeastern Brazilian coast (Rio Grande do Norte).

Figures

FIGURE 4. Collodes leptocheles Rathbun, 1894, female, cl: 42 mm, cw: 12 mm (MOUFPE 19233). A, dorsal habitus; B, ventral habitus; C, anterior carapace, dorsal view; D, anterior carapace, ventral view; E, pleon, ventral view; F, right chela, external view. Scale bars = 5 mm.