A long-finned specimen of Beryx decadactylus from off Rockall is reported and the Northeastern Atlantic persistence of juvenile characters in subadult and adult fish is discussed. 1999 The Fisheries Society of the British Isles A specimen of Beryx decadactylus Cuvier, 1829 (Figs 1 and 2) with elongate rays in the pelvic fins and with the spines on the head, especially the infraorbital spine, exceptionally strongly developed, was captured from 200 fathoms (c. 366 m) at 56 50 N 15 45 W, c. 90 miles SW of Rockall, on 7 May 1997, by the Shetland registered vessel Alison Kay (LK 57), skipper J. Anderson, whilst fishing for haddock, Melanogrammus aeglefinus (Linnaeus, 1758). The specimen was frozen for some months before being fixed in 4% formaldehyde solution and transferred to 70% industrial methylated spirits for long-term preservation. The specimen is registered in the collections of the National Museums of Scotland as NMSZ 1997.56.Morphometric data (measurements in mm, rounded down to the nearest 0·5 mm; those c100 mm taken using dial calipers, >100 mm taken using a steel rule): L T 245·0; L F 230·0; L S 205·0; L H 66·0; orbit 27.0; body depth max 109; first infraorbital spine 6·5; intestine (from insertion of pyloric caeca to anus-measured in situ against a length of twine) 77; pectoral fin max 61; pelvic fin-rays V 1 136, V 2 138, V 3 118, V 4 130, V 5 113, V 6 92, V 7 60, V 8 58, V 9 22, V 10 7.Meristic data: D IV+18; A IV+25; P 15; V 1+10; Ll 60 (63 inclusive of scales on caudal base).The genus Beryx comprises two species, B. decadactylus and B. splendens Lowe 1833.