Comprehensive DescriptionRead full entry
Itycirrhitus Randall ZBK , gen.nov.
DESCRIPTION. Dorsal rays X,12-14 (one of 34 with 14, and two with 12); anal rays III,6; pectoral rays 14, the uppermost and lower 6 unbranched; lateral-line scales 41-45; 4 rows of large scales above lateral line in middle of body; 11 large scales below lateral line to origin of anal fin; small scales on cheek in more than 12 oblique rows, extending to base of preopercular serrae; no scales in interorbital space or on snout; scales ventrally on thorax progressively smaller anteriorly, the smallest twice the size of largest scales on cheek; gill membrane across throat finely scaled; gill rakers 5 + 13-14; supraorbital ridge low and rounded anteriorly, moderately high and sharp posteriorly, not continuing posterior to eye; eye protruding slightly above dorsal profile of head; lower opercular spine not acute, forming an angle of nearly 90° in adults; upper half of preopercular margin coarsely scaled (serrae varying from 8 in juveniles to 12 in adults); exposed edge of posttemporal with 3-5 serrae; mouth slightly oblique and small, the maxilla just reaching or extending slightly posterior to a vertical at front edge of orbit; dentition typical of the family; 5 to 12 cirri on posterior flap of anterior nostril; body moderately deep, the depth 2.6-3.05 in SL (depth increasing, in general, with growth); head length 2.7-2.9 in SL; snout moderately pointed, its length 2.8-3.05 in head; orbit diameter 4.25-4.65 in head; bony interorbital width 7.4- 8.5 in head; fifth dorsal spine usually longest, 2.1-2.3 in head; a tuft of cirri from membrane near tip of each dorsal spine; first dorsal soft ray often slightly prolonged; second anal spine 1.6-1.7 in head; caudal fin truncate to slightly rounded; pectoral fins nearly as long as head, the longest rays reaching or extending beyond a vertical at origin of anal fin; pelvic fins extending beyond anus; light gray-brown, shading to white ventrally, with four slightly oblique dark brown bars on body that narrow ventrally and extend a short distance into base of dorsal fin, the first bar below first three dorsal spines, ending in a black spot above gill opening; a fifth dark bar on caudal peduncle, its upper half black; free edges of scales on body rimmed with bright red; a dark brown spot on opercle and irregular narrow brown bands across ventral part of head onto chest.
TYPE SPECIES. Cirrhitus wilhelmi Lavenberg & Yanez , 1972
TYPE LOCALITY. Easter Island.
ETYMOLOGY. Itys from the Greek for rim, in combination with Cirrhitus , in reference to the striking bright red edges on the scales of the type species.
REMARKS. When first collected, the color pattern of this species suggested that it would be placed in Amblycirrhitus ZBK , Isocirrhitus ZBK , or Cirrhitops ZBK . It was soon determined that it is generically distinct from Amblycirrhitus ZBK and Isocirrhitus ZBK by having the three supraneural bones ending in the space before the second neural spine (two supraneural bones in this space in the other two genera), 6 instead of 5 lower pectoral rays unbranched and thickened, preopercle coarsely instead of finely serrate, a longer and more pointed snout, smaller mouth, small scales on the cheek instead of four or five rows of large scales, longer dorsal spines, and 13 instead of 11 or 12 dorsal soft rays. It differs from Cirrhitops ZBK in having small scales on the cheek, about half as many preopercular serrae, a longer and more pointed snout, smaller mouth, and the uppermost instead of upper 2 pectoral rays unbranched. The specimens were initially cataloged at the Bishop Museum as “cirrhitid”.
Lavenberg & Yañez described wilhelmi in Cirrhitus , indicating that it is most closely related to C. splendens (placed here in the new genus Notocirrhitus ZBK ). In addition to the nine characters separating Itycirrhitus ZBK from Notocirrhitus ZBK in the key, Itycirrhitus ZBK differs in having a deeper body, shorter snout, narrower interorbital space, and longer dorsal and anal spines. It is distinct from the species of Cirrhitus by the following characters: three supraneural bones ending in space before second neural spine (two in Cirrhitus ); a better developed supraorbital ridge (hence a more concave interorbital space); a longer and more pointed snout; mouth ending below front of orbit (to or beyond middle of eye in Cirrhitus ); longer pectoral fins, longer dorsal and anal spines, and more deeply incised membranes of the spinous portion of the dorsal fin.
Itycirrhitus wilhelmi is known only from Easter Island and Pitcairn Island; it occurs on rocky substrata from less than 1 m to at least 55 m.
MATERIAL EXAMINED: EASTER ISLAND : BPBM 6673 , 2: 85-90.5 mm ; BPBM 6674 , 96 mm ; BPBM 6675 , 90 mm ; BPBM 6677 , 4: 66-90 mm ; BPBM 6678 , 3: 69-104 mm ; BPBM 6679 , 16: 28-74 mm ; BPBM 6680 , 2: 65-76 mm ; BPBM 6681 , 4: 54-85 mm . PITCAIRN ISLAND : BPBM 16637 , 69 mm ; BPBM 16740 , 38 mm .