Choerodon anchorago ( Bloch, 1791 )

Martin F., Martin F., 2017, A review of the tuskfishes, genus Choerodon (Labridae, Perciformes), with descriptions of three new species, Memoirs of Museum Victoria 76, pp. 1-111 : 15-18

Choerodon anchorago ( Bloch, 1791)

Anchor Tuskfish

Sparus anchorago Bloch, 1791: 108 , pl. 276, locality unknown.

Labrus macrodontus Lacepède, 1802: 451 , 522, locality unknown, specimen sent to France from Holland.

Cossyphus macrodon Bleeker, 1847: 10 , emendation of Labrus macrodontus Lacepède.

Choerops meleagris Rüppell, 1852: 20 , Mare javanicum (Java Sea).

Crenilabrus leucozona Bleeker, 1858a: 20 , Biliton ( Indonesia).

Choerops Maeander Cartier, 1874: 102, Cebu ( Philippines).

Choerodon weberi Ogliby, 1911: 52 , (listed as Chaerodon weberi on p. 36), Dobo, Aru Islands ( Indonesia).

Diagnosis. Dorsal fin rays XIII, 7; anal fin rays III, 9; pectoral fin rays ii, 13, rarely 14, dorsalmost ray of moderate length 35.0– 44.9% pectoral fin length, ventralmost rays shorter than those above, posterior edge of fin obliquely straight, dorsoposterior corner bluntly pointed, posteroventral corner angular; body deep, 37.0–45.1% SL, head depth 28.5–37.9% SL, caudal peduncle depth 12.3–17.3% SL; head bluntly pointed, dorsal profile of snout moderately steep, snout length 12.0–18.3% SL; predorsal scales approximately 7–9, reaching forward on dorsal midline to about midpoint between posterior extent of orbit and posterior edge of preopercle; cheek with small partially embedded scales in about 7–10 diagonal rows, posteriormost with about 9–15 scales to upper extent of free preopercular edge, reaching forward to or almost to corner of upper lip crease above mouth, with broad naked margin posteriorly and ventrally on preopercle; 1 or 2 rows (only about 2 scales in second row when present) of small scales on subopercle adjacent preopercular edge extending forward to about anterior end of ventral preopercular margin, with about 8 scales in outermost row; each lateral line scale with multiple branching laterosensory canal tube; scales above lateral line about 3½; cephalic sensory canal pores relatively few confined to lines or short branches associated with major canals; second pair of canines in lower jaw directed anterodorsally and slightly laterally; dorsal and anal fins with very low basal sheath comprising 2 or 3 progressively smaller accessory scales at deepest; posterior lobe of dorsal and anal fins reaching to or beyond hypural crease; caudal fin truncate, corners rounded to square; pelvic fin reaching to or just short of anus, length 21.7–28.0% SL. (See Table 3 for additional meristic and morphometric ranges.) Adults with upper third of body and head above mouth dark grey, white below, with dorsally tapering vertical white or yellow band below central dorsal fin spines and white saddle-like blotch covering top of caudal pecuncle forward to bases of middle segmented dorsal fin rays; head peppered with fine orange spots in life.

Reaches moderately large maximum size, largest specimen examined 273 mm SL.

Pigmentation in alcohol. Juveniles dark dusky with 5 vertical narrow pale bands crossing side and 2 horizontal narrow pale stripes extending from behind head to dorsal and ventral sides of caudal peduncle, anterior two pale bands crossing nape; head similarly dusky dark with pale dorsal margin to eye, middorsal pale stripe covering top of snout to above eye, horizontal pale stripe along underside of eye and pale marks on ventral surface below eye, low on operculum and on chest; small dark spots on dorsal and ventral profiles midway along and at posterior corners of caudal peduncle and at centre of caudal fin base, on leading edge, midway along and at posterior base of dorsal fin, on leading edge and at posterior base of anal fin, and extending from pectoral fin base along leading edge of pelvic fin. Larger juveniles dusky with pale underside and narrow remnants of 5 pale bands, 3rd band just posterior to pectoral fin and 5th band across anterior end of caudal peduncle most prominent; base of pectoral fin with large dark spot. Initial phase adults dusky above and pale below upper end of pectoral fin base, distinct demarcation on head at horizontal from corner of mouth; side with pale underside extending upward as dorsally tapering wedge-shaped mark behind pectoral fin with apex reaching lateral line; caudal peduncle pale except for midlateral extension of dusky pigmentation reaching to or almost to caudal fin base; dusky side of head speckled with fine pale spots; pectoral fin base covered by prominent dark spot; dorsal fin dusky above dusky area on side; remainder of dorsal fin and other fins pale. Terminal phase adults similar to initial phase but with pale area on side covering ventral 2/3 of side between front of pale wedge and vertical at middle segmented dorsal fin rays; dusky and pale areas on head and anterior end of side separated by distinctly dark margin.

Fresh colours. Juveniles olive brown to brown with 5 narrow white bands, first two crossing predorsal, third below 4th or 5th dorsal fin spines, 4th below last couple of dorsal fin spines and 5th at posterior end of dorsal fin base (fig. 2A); 2 narrow white stripes originating above and below pectoral fin base and terminating on base of caudal fin; head brown dorsally with broad white stripe under eye and narrow white stripe above eye. Dorsal, anal and pelvic fins same colour as side adjacent with continuation of white bands on side, white ocellated black spot near middle of segmented ray portion of dorsal and anal fins and dorsally and ventrally on caudal fin base, ocelli with red surround in small individuals; caudal and pectoral fins hyaline ( Okamura & Amaoka, 1997: 465, left second from top; Chen et al., 2010: 380 & 381, figs D & E; Kuiter, 2010: 51, fig. D; Allen & Erdmann, 2012: 645, left side fig. in middle of page).

Initial phase adults purplish grey dorsally with ventral half white (fig. 2B); prominent white wedge-shaped bar on side just posterior to pectoral fin and white rectangular blotch covering dorsal half of caudal peduncle and side below last 2 dorsal fin rays; pectoral fin base with black-orange-black ocellated spot; head with numerous fine orange spots, orange horizontal line from corner of mouth, several orange lines on chin. Dorsal fin purplish grey with 3 horizontal orange stripes anteriorly, one submarginal posteriorly, yellowish white basoposteriorly. Anal fin yellow with light purple margin and orange submarginal stripe. Caudal and pectoral fins yellowish orange. Pelvic fin white with lengthwise stripe just posterior to leading edge ( Okamura & Amaoka, 1997: 465, left bottom; Chen et al., 2010: 381, fig. F; Kuiter, 2010: 51, figs B & F; Allen & Erdmann, 2012: 645).

Terminal phase adults blacker posterodorsally (fig. 2C); wedge-shaped bar orange with broad orange streak extending posteriorly on lateral midline; pectoral fin base covered with large black spot preceded by orange marks; very broad black stripe on upper lip to opercular edge. Dorsal fin black anteriorly on soft portion, white posteriorly with narrow orange lines. Anal fin white with several narrow orange longitudinal lines breaking up into spots posteriorly. Caudal fin black, orange somewhat distally with narrow blue marginal line. Pelvic fin with 1 or 2 additional orange lines ( Shen, 1993: pl. 143, fig. 10; Okamura & Amaoka, 1997: 465, left second from bottom; Shibukawa, Peristiwady & Suharti, in Kimura & Matsuura, 2003: 147; Kuiter, 2010: 51, figs C & G; White et al., 2013: 265, fig. 89.13).

Etymology. The name anchorago may refer to an anchor-like colour pattern, as perceived by its author.

Distribution. One of the most widely distributed species in the genus (fig. 3), recorded from Sri Lanka ( Munro 1955:185), Nicobars and Andaman Islands in the north-eastern Indian Ocean, throughout the tropical western Pacific from southernmost Japan and the Ogasawara Islands ( Randall et al., 1997: 45) to the northern Great Barrier Reef in north-eastern Australia, eastward to Palau and Yap in Micronesia ( Myers, 1999: 189), Solomons, Vanuatu and New Caledonia ( Fricke and Kulbicki, 2006: 386). Occurs in coastal seagrass and sandy areas with mixed coral and rubble to depths of about 25 m.

Comments. The specimens on which Bloch (1791) and Lacepède (1802) based their descriptions of Sparus anchorago and Labrus macrodontus , respectively, were acquired from the Netherlands, presumably from auctions, and lacked provenance. Although Bloch’s accompanying figure (1791, pl. 276) did not accurately portray the distinctive colour pattern of this species, the morphological description, including dorsal, anal and pectoral fin ray counts, is diagnostic for this species. Paepke (1999: 92) identified two specimens in the Berlin Zoological Museum collection as types, one of which has apparently been lost, and designated the extant specimen (ZMB 2476) as lectotype. The type of Lacepède’s description is likewise identifiable as this species by the same characters, as is the type specimen (MNHN A.8208). Bleeker (1849) emended Lacepède’s name to Cossyphus macrodon without justification and based his detailed description on three specimens from Batavia (Java, Indonesia).

Choerops meleagris , the type species of Rüppell’s (1852) new genus, was presented only with a description of morphological features, which are common to species of the genus. The Senckenberg Museum type (SMF 2759, 263 mm SL) is a dried specimen clearly identifiable as C. anchorago . The type of Bleeker’s (1858) Crenilabrus leucozona , now in the British Museum (BMNH 1864.5.15.18), is a 34.3 mm SL (42 mm TL) specimen with the characteristic meristic values and juvenile colouration of C. anchorago . Choerops Maeander Cartier, 1874 was based on juveniles according to the lengths of his type series 3.9–6.7 cm from Cebu in the Philippines. Although the types were not located, Cartier’s account includes a detailed description that matches the juvenile colouration of C. anchorago , and his anal fin count of “3/9” (III, 9) is unique for that species within the genus. Ogilby’s C. weberi was based on seven specimens, 121–197 mm, from Dobo, Aru Islands, three of which (QMB I.20, I.1532, and I.10133) are still present in the Queensland Museum collection. The species is synonymous with C. anchorago .

Choerdon anchorago is the most often encountered member of the genus, being found in shallow waters of the central western Pacific, and one of the few ranging westward in the northern part of the Indian Ocean as far as India and Sri Lanka. Its nine segmented dorsal fin rays and vertebral count of 11 + 16 are distinctive for the subgenus and in combination for the family.

Material examined. 163 specimens, 12–273 mm SL; see appendix.

Choerodon cauteroma Gomon & Allen, 1987