(Fig. 1 A, B, C)
Acanthephyra acanthitelsonis Spence Bate 1888: 745, pl. 125, fig. 3.— Kemp 1906: 8; 1939: 574.— Balss 1925: 254.— Chace 1936: 27; 1947: 16; 1986: 9.— Barnard 1950: 668.— Holthuis 1951: 27.— Springer & Bullis 1956: 11.— Crosnier & Forest 1968: 1129; 1973: 31.— Culkin & Morris 1969: 112.— Hopkins et al. 1989: 6.— Hopkins et al. 1994: 146.— Allen et al. 2000:276.— Burghart et al. 2007: 319.— Muñoz et al. 2012:478.— Cardoso 2013: 210.— Cardoso et al. 2014: 52.
Material examined. 21 individuals, 14 F (TL: 58,9–64,8 mm; CL: 33,4–39,6 mm) and 7 M (TL: 48,2–56,7 mm; CL: 12,6–18,2 mm), Rocas Atoll, #ST–14, Leg. 2 Mid, 512 m, 03°58’ S–34°03’ W, 0 5 October 2015, MOUFPE 15.580. 34 individuals, 19 F (TL: 62,3–77,4 mm; CL: 38,5–41,4 mm) and 15 M (TL: 62,3–69,7 mm; CL: 17,4– 19,9 mm), Rocas Atoll, #ST–22, Leg. 1, 525 m, 04°07’ S–33°47’ W, 10 October 2015, MOUFPE 15.597. 17 individuals, 9 F (TL: 98,7–104,4 mm; CL: 19,4–39,7 mm) and 8 M (TL: 65,1–74,2 mm; CL: 27,6–38,8 mm), Rocas Atoll, #ST–51, Leg. 1, 616 m, 08°56’ S–34°29’ W, 0 5 October 2015, MOUFPE 15.588.
Diagnosis. Carapace smooth, middorsal region slightly elevated posteriorly; rostrum slender and subequal to scaphocerite, slightly turned up, dorsal margin armed with 7–9 small teeth, ventral margin armed with 4–5 teeth, basis with dense setules; antennal spine present; branchiostegal spine present, with distinct carina extending backwards on to carapace for three times the spine length. Pleon smooth, laterally compressed, dorsally carinated (except pleonite 1). Pleonite 1 notched in the median line. Pleonite 3 posterodorsal angle produced into a long tooth, reaching halfway of pleonite 4. Pleonite 4–6 with a posterodorsal angle produced into a short tooth. Male pleopod 2 appendix interna with dense setae on distal margin, appendix interna 0.9 length of appendix masculina. Telson longer than uropods, slender, armed with 13–19 pairs of dorsolateral spines and 2 pairs of distal spines (Modified from Spence Bate 1888).
Geographic distribution. (Fig. 2) Atlantic Ocean: Iceland (Faroe island), USA (off Florida, New Jersey, South Carolina, Virginia), Bermuda, Gulf of Mexico, Bahamas, Caribbean Sea, off French Guiana, Brazil (Rocas Atoll, first record). Central Atlantic: South Equatorial-Mid Atlantic Ridge; Eastern Atlantic: off Guinea Bissau, Sierra Leone, off Gabon, off Congo, off Angola, off Namibia (Spence Bate 1888; Kemp 1939; Chace 1947, 1986; Fenner & Chace 1947; Crosnier & Forest 1968, 1973; Hopkins et al. 1989; Hopkins et al. 1994; Burghart et al. 2007; Muñoz et al. 2012; Cardoso 2013; Cardoso et al. 2014).
Bathymetric distribution. Occurring between 230–4000 m, but more abundant between 230–500 m (Chace 1947; Crosnier & Forest 1967, 1968). The material examined fits well in the range previously observed between 512– 616 m.
Remarks. In this study, the females were more abundant and larger than males, being the results different from the ones found by Crosnier & Forest (1973) who found males larger than females off the African coast, between São Tomé and Angola. The specimens analyzed herein do not differ from the description of Crosnier & Forest (1973). According to Kemp (1939) and Cardoso (2013), this species is included in the group of Acanthephyra purpurea A. Milne-Edwards, 1881a, especially for the presence of pairs of dorsolateral spines on the telson, varying between 3–19 pairs of dorsolateral spines. Among this group, two similar species resemble A. acanthitelsonis, such as: Acanthephyra kingsleyi Spence Bate, 1888, occurring in eastern Atlantic, and Acanthephyra pelagica (Risso, 1816), occurring in eastern Atlantic, Mediterranean, and southern Indo-Pacific Ocean. However, A. kingsleyi have 3–6 pairs of dorsolateral spines on telson and A. pelagica have 7–11, whereas A. acanthitelsonis have 13–19 (fig. 1C) (Crosnier & Forest 1973; Chace 1986).