Head and otolith morphology of the genera Hymenocephalus, Hymenogadus and Spicomacrurus (Macrouridae), with the description of three new species Author Schwarzhans, Werner text Zootaxa 2014 2014-11-28 3888 1 1 73 journal article 10.11646/zootaxa.3888.1.1 1175-5326 10086415 1B437AE1-CF28-4C1B-95B6-C31A295905A0 Spicomacrurus adelscotti ( Iwamoto & Merrett, 1997 ) Figs. 3C–D , 4A–B , 5 Hymenocephalus (Spicomacrurus) adelscotti Iwamoto & Merrett, 1997: 514 ( type locality: 11°54’S , 179°31’W ); Iwamoto & Williams, 1999: 176 . Material examined. 1 specimen WAM P.28073-004, 154+ mm TL, 17°45’S , 118°32’E , 600– 690 m . Diagnosis. Pelvic fin rays 9; nasal bones closely adjoining along mesial edges, forming three horizontal platelike processes; OL:OH = 1.75. Comparison. Spicomacrurus adelscotti most closely resembles S. kuronumai , differing in the number of pelvic fin rays (9 vs 8), the more elongate head shape (head length: height = 2.1 vs 1.7) and the more elongate otolith (OL:OH = 1.75 vs 1.45–1.6). The occiput does not show any relict of scales or scale pockets as do the studied specimens of S. kuronumai . Description. Head morphology ( Figs. 3C–D ): Head length to height about 2.1 with relatively firm head bones and platy spatulate nasal bones closely adjoining along mesial edges. No indication of scales on head. Snout length 26% HL, orbit diameter 29% HL, interorbital width 40% HW. Barbel 18% HL, reaching vertical through center of orbit. Infraorbital, supraorbital and preopercular canal systems narrow with widths <8% HL, covered by rather thick, firm skin. One small pore visible in anterior section of infraorbital skin. Preopercular angle broad, not projecting. Otolith morphology ( Fig. 4A–B ): Thin, elongate otoliths with slightly convex inner and slightly concave outer face. OL:OH = 1.75; OH:OT = 4. Predorsal lobe moderately developed, narrow; ventral rim shallow; anterior tip blunt, posterior tip moderately pointed. Sulcus slightly supramedian with narrow, ventrally-indented collum. Colliculi large, reaching close to anterior and posterior rims of otolith, caudal colliculum about 1½ times the length of ostial colliculum; pseudocolliculum indistinct, short; TCL:PCL = 9. Dorsal depression large; ventral furrow distinct, turning upwards and away from ventral rim posteriorly. Distribution. ( Fig. 5 ) Known from only two specimens , the holotype off northern Fiji , and the examined specimen from off Western Australia.