Alepocephalus rostratus Risso, 1820 —Risso's smooth-head
72 specimens were caught at depths between 781 and 1,683 m. Length data were available for 51 specimens ranging from 18 to 65 cm TL (43.7 ± 13.2). Habitat and Distribution: bathydemersal, over soft bottoms at about 300–3,600 m depth, usually at 300–1,600 m. Eastern Atlantic Ocean, from Iceland to Namibia and western Mediterranean Sea. Vulnerability: DD (IUCN), HHV (FishBase).
Alepocephalus bairdii Goode & Bean, 1879 —Baird's smooth-head
1,895 specimens were caught at depths between 711 and 1,809 m. Length data were available for 1,228 specimens ranging from 13 to 89 cm TL (64.4 ± 12.1). Biometry and meristic: 6 specimens 521–817 mm TL, 443– 708 mm SL; HL: 23.8–28.3; PO: 4.5–5.1; POL: 14.4–17.4; ED: 4.6 –7.0; IOW: 3.4–4.4; PD: 55.6–66.4; LD: 12.4– 15.4; PA: 56.1–68.9; LA: 13.8–17.2, PP: 24.6–29.9; PV: 40.6–49.2; LP: 7.7–11.5; LV: 4.9–5.6; H: 17.8–20.5; D: 20–22; A: 21–24; P: 10–13; V: 8–9; Gr: 8–11 + 1 + 18–19; SLL: 61–64. Habitat and Distribution: bathydemersal over ooze and sand bottoms at a depth range of 365–2,500 m. Eastern Atlantic Ocean, from Greenland and Iceland southward to 17 °N and western Atlantic Ocean, from Greenland to Grand Banks and 29 ° 52 'N, 77 °09'W. Vulnerability: DD (IUCN), HHV (FishBase).
Xenodermichthys copei (Gill, 1884) —Bluntsnout smooth-head
69 specimens were caught at depths between 735 and 1,640 m. Length data were available for 49 specimens ranging from 6 to 19 cm TL (14 ± 2.8). Habitat and Distribution: mesopelagic to benthopelagic as adults, between 100–2,650 m, usually at 100–1,230 m depth. Widely distributed in the Atlantic, eastern Pacific and Indian oceans. Vulnerability: DD (IUCN), MV (FishBase).
Rouleina attrita (Vaillant, 1888) —Softskin smooth-head
248 specimens were caught at depths between 1,470 and 1,809 m. Length data were available for all specimens, ranging from 6 to 49 cm TL (25.4 ± 9.6). Habitat and Distribution: bathypelagic at depth range 450– 2,300 m. Circumglobal, widely distributed in the Atlantic, most Indian submarine ridges, Subantarctic, North Pacific and tropical western and eastern Pacific oceans. Vulnerability: DD (IUCN), MHV (FishBase).
Conocara macropterum (Vaillant, 1888) —Longfin smooth-head
41 specimens were caught at depths between 1,674 and 1,809 m. Length data were available for all specimens ranging from 17 to 39 cm TL (30.7 ± 4.7). Habitat and Distribution: epibenthic at about 800–2,677 m depth, usually at 1,200–1,800 m. Known from widely scattered localities on both sides of the Atlantic Ocean, in eastern Atlantic from 54 °N to 45 °S and in western Atlantic in Bahamas, Gulf of Mexico and off Brazil. Vulnerability: DD (IUCN), MHV (FishBase).