Lepteces ornatus Rathbun, 1893

(Figs. 1‒3)

Lepteces ornatus Rathbun, 1893: 84, pl. 6 fig. 1; 1925: 292, fig. 98, pl. 244 fig. 2— Melo & Crivelaro 2002: 777, fig. 1— Ng et al. 2008: 103 (list).

Material examined. 1 male, cl: 7.8 mm, cw: 12 mm (MOUFPE 15648), 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 (Yucatan channel – type locality) (Rathbun 1893); Uruguay (off Cabo Polonio) (Melo & Crivelaro 2002); Brazil (Rio Grande do Norte) (present study).

Commonly found between 180 and 250 m depth (Rathbun 1893; 1925; Melo & Crivelaro 2002).

Remarks. Lepteces ornatus fits well with the original description provided by Rathbun (1893; 1925). Based on that we include some new characters to the original description:

Carapace subpyriform, slightly convex, densely tuberculated, with hooked setae, interspaced with simple long setae. Tubercles in gastric, branchial, cardiac regions forming circular row in form of flat-topped mushrooms, while in intestinal region tubercles form semicircle row (Fig. 1 A–E). Rostrum long, bifurcate, covered with curled robust setae (Fig. 1B, C). Preorbital spine present, long, acute, strongly curved upwards (Fig. 1B). Eyestalk long, pedunculated, fitting in orbital cavity (Fig. 1B). Postorbital spine present forming two hiatuses (Fig. 1B). Basal article of antenna with outer margin convex, with strong spine directed forward forming antero-lateral angle (Fig. 1C). Antennular flagellum surpassing rostrum (Fig. 1B). Antennular fossae vertical, conical; inter-antennular septum like inverted triangle with small spines (Fig. 1C); epistome sharply recessed at middle. Ischium of third maxilliped longer than merus with internal margin crenulated (Fig. 2B). Chelipeds slender, shorter than pereopod 2 (Fig. 2C); fingers much shorter than palm; without setae. Pereopods 2–5 (ambulatory legs 1–4) strongly armed with longitudinal rows of robust spines, on inner, outer, dorsal margins (Fig. 2 D–G); surface densely tuberculate except off distal portion of dactylus; robust spines decreasing in size from P2 to P5, with scattered plumose setae along the surface; merus of P2, P3 with few distal setae. Pleonal somites free, densely granulated, telson smooth (Fig. 1D). Gonopod 1 (G1) well developed, slightly convergent at midline of thoracic sternum, wide base, slightly curved at the middle, curved at tip (Fig. 3A). Gonopod 2 (G2) straight, smooth, short, almost one-fifth length of G1, stout (Fig. 3B).

The first record of L. ornatus from the southwestern Atlantic was made by Melo & Crivelaro (2002) based on a female from Uruguayan waters (34°45’S, 52°05’W, 180 m, station GEDIP#1881 – MZUSP: 6126), mistakenly referred to as “ Rio Grande do Sul (Brazil)”. Lepteces ornatus can be found beneath coral reefs and on sandy bottoms along the continental shelf and slope between 180 and 250 m depth (Rathbun 1893; 1925; Melo & Crivelaro 2002). The Brazilian specimen was found at 180 m, in gravel and muddy bottoms, corroborating with the observations provided by Rathbun (1893; 1925) and Melo & Crivelaro (2002).