A revision of the genus Muricea Lamouroux, 1821 (Anthozoa, Octocorallia) in the eastern Pacific. Part I: Eumuricea Verrill, 1869 revisited Author Breedy, Odalisca Author Guzman, Hector M. text ZooKeys 2015 537 1 32 http://dx.doi.org/10.3897/zookeys.537.6025 journal article http://dx.doi.org/10.3897/zookeys.537.6025 1313-2970-537-1 69EB93DFE3CF4B50BE4B6F997AEDB51C Taxon classification Animalia Alcyonacea Plexauridae Genus Muricea Lamouroux, 1821 Muricea Lamouroux, (pars) 1821: 36; Blainville (pars) 1834 : 509; Ehrenberg (pars) 1834 : 134; Dana 1846 : 673; Milne Edwards and Haime 1850: 142; Koelliker 1865 : 135; Verrill 1868b : 411; Verrill 1869a : 418-419, 450; Studer 1887 : 58; Wright and Studer 1889 : 93; Gorzawsky 1908 : 8; Nutting 1910 : 9; Kuekenthal 1919 : 835; 1924 : 141; Riess 1929 : 383-384; Aurivillius 1931 : 102-104; Deichmann 1936 : 99 ; Bayer 1956 : F210; 1959 : 12; 1961 : 179-180; 1981 : 930 (in key); 1994 : 23-24; Tixier-Durivault 1969- 1970 : 154; Harden 1979 : 140; Hardee and Wicksten 1996 : 127-128; Marques and Castro 1995 : 162; Castro et al. 2010 : 779. Eumuricea (pars) Verrill 1869a : 449; Riess 1929 : 397; Studer 1887 : 58; Wright and Studer 1889 : pl LVI; Nutting 1909 : 718; Thomson and Simpson 1909 : 258; Thomson 1927 : 48-49; Kuekenthal 1919 : 836; 1924 : 149-150; Riess 1919: 397-398; Aurivillius 1931 : 50 (emended); Deichmann 1936 : 104. Eumuricea (Muricea) Bayer 1981 : 930 (in key). Type species. Muricea spicifera Lamouroux, 1821, by subsequent designation: Milne Edwards and Haime 1850. [ Muricea spicifera was later synonymised with Muricea muricata (Pallas, 1766) apud Bayer 1961 : 179-180] Diagnosis (based on Bayer 1961 , 1994 ; Marques and Castro 1995 ; Castro et al. 2010 ). Colonies planar or multiplanar, bushy, arborescent, laterally branched, pinnately branched, dichotomous or with long flexible branches without occasional branch anastomosis. Branches and branchlets upward bending almost parallel, and with about the same thickness all along, frequently with slightly enlarged tips. Coenenchyme moderately to very thick (compared to other plexaurids) with a circle of longitudinal canals surrounding the axis and dividing the coenenchyme into a thin inner layer or axial sheath, and a thicker outer layer. Polyps fully retractile within prominent calyces longitudinally and closely placed and at all sides of the branches. Calyces prominent, shelf-like or tubular, with prickly projecting spindles, longitudinally arranged, imbricate or not. Anthocodial sclerites mainly small spindles, in weakly differentiated transverse collaret and points below the tentacles, or just with some sclerites scattered along the neck zone of the polyp. Sclerites of the outer coenenchyme mostly long, unilateral spinous spindles, often massive, sculptured on inner surface by crowded complex tubercles and on outer surface by simple spines or prickles, and in some species with a few more or less prominent coarse, prickly projections. Axial sheath composed of capstans, spindles, or oval forms. Sclerite colours white, various hues of yellow, amber, orange, purple and red. Anthocodials with lower colour hues. Distribution. From Cape Hatteras, North Carolina to Brazil, including Bahamas, Greater and Lesser Antilles, and Caribbean islands ( Bayer 1961 ); in the eastern Pacific from southern California to Peru. The genus occurs at depths down to 200 m, but normally found less than 100 m. Muricea midas Bayer, 1959 is the deepest record for the genus in the western Atlantic, 146 m ( Bayer 1959 ); and Muricea galapagensis Deichmann, 1941 in the eastern Pacific, 91 m. Remarks. Colony shape and branching patterns are variable among Muricea species. The shape of calyces shelf-like or tubular, and related features as being imbricate or sparse show many intermediate forms. In the tubular-calyces species group the apical branches show a closer arrangement of calyces and smaller projecting angles in respect to the branch than at the lower branches. Therefore, the strongest character that separates Muricea from other genera is the type of sclerites.