DeGruy’s chromis

description

(Figs. 4 a – 4 c; Table 5; Morphbank 122; DigiMorph 123; GenBank 124; Barcode 125)

Five new species of the damselfish genus Chromis (Perciformes: Labroidei: Pomacentridae) from deep coral reefs in the tropical western Pacific

description

Description. Dorsal rays XIV, 12 (one paratype with XIII, another with 11); anal rays II, 12 (one paratype with 11); all dorsal and anal rays branched, the last to base in some specimens; pectoral rays 18, the upper 2 and lowermost unbranched; pelvic rays I, 5; principal caudal rays 8 + 7 = 15; upper and lower procurrent caudal rays 5, the anterior 3 spiniform, the posterior 2 segmented and unbranched; tubed lateral-line scales 16 | 15 (15 – 17, one paratype with 17); posterior midlateral scales with a pore or deep pit 8 | 9 (5 – 9); scales above dorsal fin to origin of dorsal fin 3; scales below lateral line to origin of anal fin 9 (one paratype with 8); gill rakers 7 + 20 = 27 (7 + 20 – 21 = 27 – 28); surpaneural (predorsal) bones 3; vertebrae 12 + 13. Body moderately deep, depth 1.84 (1.92 – 1.99) in SL, and compressed, the width 2.87 (2.73 – 3.29) in body depth; head length 3.10 (2.95 – 3.18) in SL; dorsal profile of head with slight convexity anterior to eye, very slight concavity dorsal to eye, and very slight convexity on nape; snout shorter than orbit diameter, its length 4.05 (3.63 – 4.38) in head length; orbit diameter 2.77 (2.12 – 2.95) in head length; interorbital space

Five new species of the damselfish genus Chromis (Perciformes: Labroidei: Pomacentridae) from deep coral reefs in the tropical western Pacific

diagnosis

Diagnosis. Dorsal rays XIII – XIV, 11 – 12 (usually XIV, 12); anal rays II, 11 – 12 (usually 12); pectoral rays 18; spiniform caudal rays 3; tubed lateral-line scales 15 – 17; gill rakers 7 + 20 – 21 (total 27 – 28); body depth 1.84 – 1.99 in SL; color of adults when fresh dull brownish yellow with nine thin lavender-gray stripes on side of body, with a prominent black spot on dorsal half of pectoral-fin base.

Five new species of the damselfish genus Chromis (Perciformes: Labroidei: Pomacentridae) from deep coral reefs in the tropical western Pacific

discussion

Remarks. The habitat of this species is similar to that of other species described herein: deep outer-reef slopes at depths of 85 – 120 m, usually in the vicinity of rock outcrops with small holes and caves, and around limestone talus. It is generally not as abundant as other species of Chromis described here, usually found in small groups and observed feeding low in the water column. The species appears most similar to other deep-dwelling species of Chromis described previously (see Remarks section of C. abyssus). Juveniles superficially resemble C. opercularis 136 (Günther in Playfair and Günther 1867) in color, but are easily distinguished from that species on several morphological characters (e. g., usually XIV dorsal-fin spines in C. degruyi, vs. XIII in C. opercularis; body depth 1.84 – 1.99 in SL vs. 2.1 – 2.3 in C. opercularis), as well as adult coloration. Some aspects of the adult coloration are similar to C. planesi Lecchini and Williams 2004, but C. degruyi differs from that species in many other aspects of adult coloration as well as number of pectoral-fin rays (20 in C. planesi vs. 18 in C. degruyi), dorsal-fin soft rays (usually 13 vs. usually 12), and tubed lateral-

Five new species of the damselfish genus Chromis (Perciformes: Labroidei: Pomacentridae) from deep coral reefs in the tropical western Pacific