Aseraggodes auroculus, Randall, 2005

Randall, John E., 2005, A review of soles of the genus Aseraggodes from the South Pacific, with descriptions of seven new species and a diagnosis of Synclidopus., Memoirs of Museum Victoria 62 (2), pp. 191-212 : 195-197

Aseraggodes auroculus sp. nov.

Figure 2 , Tables 1–4

Holotype. ROM 61358 , 35.5 mm, Society Islands , Moorea, off NW coast, 17°31'0''S, 149°55'30''E, reef slope of coral rubble, with some live coral (including a few large heads of Porites ), 18–24 m, rotenone, R. Winterbottom and R. Mooi, 10 Dec 1989.

Paratypes. ROM 61357 , 34.0 mm, Society Islands , Moorea, W side of pass off Maharepa about middle of its length, 17°29'24''S, 149°48'0''W, 15–18 m, steep slope with coral rubble, sand, and a 3-m wall, rotenone , R. Winterbottom and R. Mooi, 5 Dec 1989 ; BPBM 39690 , 30.4 mm and USNM 381623 , 29.8 mm, same data as holotype .

Diagnosis. Dorsal rays 74–77; anal rays 56–57; most dorsal and anal rays double branched; lateral-line scales 69–73, including 6–7 anterior to a vertical at upper end of gill opening; vertebrae 37–38; dorsal pterygiophores anterior to fourth neural spine 12; body depth 2.45–2.6 in SL; HL 3.85–3.95 in SL; eye diameter 4.55–4.9 in HL; upper eye overlapping a anterior two-thirds to three-fourths of lower eye; interorbital space narrow, the vertical distance separating eyes about one-fourth to one-sixth eye diameter; no caudal peduncle; short fleshy cirri on ventral edge of head; lateral line aligned with ventral part of upper eye; longest dorsal ray 1.55–1.7 in HL; caudal fin rounded, its length 4.4–4.55 in SL; pelvic fins 2.4–2.7 in HL, the tip of longest ray reaching base of second or third anal ray; colour of ocular side in alcohol pale yellowish brown with 3 rows of large irregular blackish blotches, one dorsal, one ventral, and one midlateral; a few small dark spots on fin rays; blind side of body pale yellowish, the dark spots on rays faint.

Description. Dorsal rays 75 (74–77); anal rays 56 (56–57); dorsal rays branched except first 9 dorsal rays of holotype and first 19 of smallest paratype; anal rays branched; caudal rays 18, the middle 16 of holotype double-branched (middle 12–14 of paratypes double-branched); pelvic rays 5, branched except first; lateral-line scales 69 (71–73), including 6–7 anterior to a vertical at upper end of gill opening; scales above lateral line on ocular side to dorsal-fin base about 22; scales below lateral line to anal-fin base about 24; vertebrae 37 (37–38); erisma (counted as the first dorsal pterygiophore) about twice as thick as remaining pterygiophores, its inner half narrowly branched; next 2 pterygiophores before tip of second neural spine; space between second and third neural spines with 6 pterygiophores; space between third and fourth neural spines with 3 pterygiophores; total of 12 dorsal pterygiophores anterior to fourth neural spine; ventroanterior margin of urohyal forming an angle of about 80°, the corner broadly rounded.

Body depth 2.6 (2.45–2.55) in SL; body width (thickness) 5.3 (4.7–5.75) in body depth; ventral profile of head posterior to mouth slightly convex; HL 3.95 (3.85–3.95) in SL; snout length 2.7 (2.6) in HL; eye diameter 4.6 (4.55–4.9) in HL; upper eye overlapping anterior two-thirds to three-fourths of lower eye; least vertical interorbital width 3.55 (2.75–3.35) in HL; upper end of gill opening on a horizontal passing about one-half eye diameter ventral to lower eye; no caudal peduncle (base of last two or three anal rays posterior to base of lowermost caudal ray); depth at base of caudal fin 1.9 (1.8–1.95) in HL.

Maxilla extending to below front edge of pupil, the upper-jaw length (measured on blind side) 2.9 (2.9–2.95) in HL; blind side of upper and lower jaws with a dense band of villiform teeth (difficult to see because just medial to a labial fold); no teeth on ocular side of jaws; tubular anterior nostril of ocular side membranous, just above upper lip, anterior to upper edge of lower eye, slightly tapering, reaching a little posterior to front edge of eye when laid back, its length about three-fourths eye diameter; posterior nostril an oblique slit in labial groove directly in front of dorsal half of lower eye; anterior nostril of blind side a more slender, slightly tapering, membranous tube above about middle of upper lip; posterior nostril of blind side a shorter, broader membranous tube posterior and slightly dorsal to anterior nostril (internarial distance about three-fourths eye diameter).

Scales ctenoid on both sides (except those of lateral line partially embedded); scales of ocular side of body with 6–9 cteni; about 2 rows of scales in interorbital space, with about another 5 rows extending onto medial and anterior part of each eye; scales on ocular side of head progressively smaller anteriorly and ventrally with fewer cteni, replaced on snout by fleshy papillae; scales on blind side of head anterior to a demarcation just posterior to end of jaws replaced by a dense zone of fleshy papillae that are progressively longer anteriorly, about 15 visible on ventral edge of head posterior to mouth (long for papillae, but too stout and short to call cirri). Lateral line straight on both sides along middle of body, projecting on ocular side toward ventral edge of upper eye; lateral line of blind side replaced by a row of sensory papillae on head (differentiated from surrounding papillae by a narrow papilla-free zone on each side), which curves ventrally at front of head; supratemporal branch of lateral line on blind side of head clearly visible as a similar row of low sensory papillae just below basal sheath of scales, becoming faint at end of about anterior third of body.

Each dorsal and anal ray with a thin lengthwise membranous ridge, narrowing distally; ridges progressively less developed posteriorly; small scales and papillae extending out on ridges of both sides of about first 20 dorsal rays, making edges of membranous ridges jagged; about basal fourth of caudal fin with progressively smaller scales on both sides to at least three-fourths length of fin.

Origin of dorsal fin anterior to lower edge of upper eye, the predorsal length 4.1 (4.15–4.4) in HL; first dorsal ray (only the tip free) 3.8 (3.7–3.95) in HL; longest dorsal ray 1.65 (1.55–1.7) in HL; origin of anal fin below base of 20th dorsal ray, slightly posterior to a vertical at end of opercular membrane, the preanal length 3.3 (3.35–3.4) in SL; length of first anal ray 3.6 (3.9–3.95) in HL; longest anal ray 1.65 (1.5–1.7) in HL; caudal fin rounded, 4.45 (4.4–4.45) in SL; pelvic fin bases adjacent on ventral edge of body, third and fourth pelvic rays longest, reaching to base of second or third anal ray, 2.5 (2.4–2.7) in HL; anus anterior to first anal ray; genital papilla dorsoposterior to anus, not connected by membrane to ocular-side pelvic fin.

Colour of ocular side of holotype when fresh: brownish yellow with numerous whitish blotches about half eye diameter in size, many interconnected; three rows of very irregular, large, blackish blotches, the dark pigment on scale edges, or isolated scales entirely black; a small squarish white spot behind upper end of gill opening; eyes golden with faint blackish bands, partly rimmed in black; fins with translucent membranes and brownish yellow rays, some with 1 or 2 blackish spots; scaly basal part of caudal fin coloured like body.

Colour of ocular side of holotype in alcohol: pale yellowish brown with 3 rows of large irregular blackish blotches, one dorsal, one ventral, and one midlateral; a few small dark spots on fin rays; blind side of body pale yellowish, the dark spots faint.

Etymology. The species name auroculus is from the Latin aurum for gold and oculus for eye, in reference to the bright golden colour of the eyes.

Remarks. The four specimens of this species were collected in 1989 off Moorea in two rotenone stations from steep sloping bottoms dominated by coral rubble at depths of 15– 24 m. They were deposited in the Royal Ontario Museum with a tentative identification of Aseraggodes melanostictus (Peters) , the name often given to specimens of soles of this genus with an ocular-side colour pattern of large blackish blotches. Although sharing the same number of dorsal rays, vertebrae, and dorsal pterygiophores with A. melanostictus , A. auroculus is easily distinguished by a higher count of anal rays, fewer lateral-line scales ( Tables 2 and 3), and having branched instead of unbranched dorsal and anal fin rays. It also appears to be a much smaller species. The two known specimens of A. melanostictus measure 74 and 86.5 mm SL.

Aseraggodes auroculus is more closely related to A. cyclurus , also collected from the Society Islands. One rotenone station resulted in a specimen of both species. The two are separated by dorsal- and anal-ray counts and differences in body depth, eye size, and length of the caudal fin (see Key). Also, A. cyclurus seems to be a larger species. The three Society Islands specimen range from 61.5 to 73.3 mm SL, compared to 29.8–35.5 mm for the four type specimens of auroculus . The 34.0 mm paratype of A. auroculus is a fully mature female.

The photograph taken of the holotype of Aseraggodes auroculus ( Fig. 2 ), shows a broad interorbital space, about three-fourths the diameter of the lower eye. The interorbital width of the preserved specimen is only one-fourth the eye diameter. The same shrinkage of the interorbital space was noted for one specimen of A. lenisquamis (see description below).

Figures

Figure 2. Holotype of Aseraggodes auroculus, ROM 61358, 35.5 mm, Moorea, Society Islands (R. Winterbottom).