Aseraggodes lateralis, 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 : 199-201

Aseraggodes lateralis sp. nov.

Figures 7 , 8, Tables 1–3, 6

Holotype. BPBM 10992 , 64.2 mm, Marquesas Islands , Ua Huka, W side, small bay 0.4 miles NE of Motu Takatai, N side of bay in 4.5–9 m, rotenone, J.E. Randall, J. R. Haywood, and R. M. McNair, 7 May 1971.

Paratypes. BPBM 12757 , 27.8 mm, Marquesas Islands , Nuku Hiva, Sentinelle de l’Est, W side, steep rocky slope with no visible sand, 23 m, quinaldine, J.E. Randall and D.B. Cannoy, 17 May 1971 ; USNM fin; lateral line as a broken black line.

Description. Dorsal rays 77, the first 15 branched, remaining rays double-branched; anal rays 58 (59), all double branched; caudal rays 18 (uppermost and lowermost rays branched, the middle 16 double branched; pelvic rays 5, all branched; lateral-line scales 78 (79–83), including 7–8 anterior to a vertical at upper end of gill opening; scales above lateral line on ocular side to dorsal-fin base about 28; scales below lateral line to anal-fin base about 29; vertebrae 37 (38); erisma (counted as the first dorsal pterygiophore) nearly 3 times thicker than remaining pterygiophores, its inner three-fourths 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 angle of about 80°, the corner strongly rounded.

Body oval and deep for genus, the depth 2.0 (2.35–2.4) in SL; body thin, the width 6.2 (5.7–5.8) in body depth; ventral profile of head posterior to mouth slightly convex; HL 4.5 (4.45–4.6) in SL; snout length 2.95 (2.95–3.0) in HL; eyes small, the eye diameter 5.85 (5.35–5.6) in HL; upper eye of holotype directly above lower (overlapping about anterior two-thirds of lower eye in paratypes); least vertical interorbital space 7.65 (10.7–10.9) in HL; upper end of gill opening at level of ventral edge of lower eye; no caudal peduncle (base of lowermost caudal ray ending above base of last anal ray); depth of body at base of caudal fin 1.45 (1.6–1.75) in HL.

Scales of both sides ctenoid (except cycloid on lateral line and partially embedded), usually with 10 cteni (a few with 11 or 12); 4 rows of scales in interorbital space, with small scales extending broadly onto median and anterior edge of eyes (apparently lost in some); scales progressively shorter anteriorly on head and with fewer cteni (front of snout with very small scales without cteni, but not in the form of little papillae or tubercles); anterior edge of snout and ventral edge of head with a row very fine cirri (especially fine anteriorly on snout); no cirri along edge of operculum; opercular membrane in form of a short triangle near upper end of gill opening. Lateral line straight on both sides along middle of body, on ocular side aligned with ventral third of upper eye; an indistinct supratemporal branch of lateral line on blind side of head, continuing faintly aanteriorly on body along base of dorsal fin.

Dorsal and anal fins with a basal sheath of 2 to 3 rows of scales; ocular side with small scales continuing a short distance out on rays and adjacent membrane on first 31 rays of dorsal fin of ocular side of holotype, and on the first 8 rays of ocular side of anal fin; scales extending out on rays of dorsal and anal rays of blind side except for last 21 rays of dorsal fin and last 33 of anal fin; a thin lengthwise membranous scaly ridge basally on anterior dorsal and anal rays of both sides, progressively shorter posteriorly; about basal third of caudal fin with scales on both sides, and well-spaced tiny scales, still with cteni, continuing on each side of rays about half way out in fin.

Origin of dorsal fin anterior to lower edge of upper eye, the predorsal length 4.95 (4.45–4.65) in HL; first dorsal ray 4.85 (4.15–5.2) in HL; longest dorsal ray 1.65 (1.5–1.55) in HL; origin of anal fin below base of 20th dorsal ray and in line with posterior end of operculum, the preanal length 3.35 (3.45–3.5) in SL; anus anterior to first anal ray; genital papilla dorsoposterior to anus; first anal ray 3.05 (2.95–3.3) in HL; longest anal ray 1.6 (1.5–1.55) in HL; caudal fin rounded to slightly pointed, 5.25 (4.7–4.8) in SL; pelvic fins close together anteriorly on ventral edge of body, their origins adjacent; third pelvic ray of each fin longest, reaching base of third anal ray, 2.85 (2.75–2.8) in HL.

Colour of ocular side in alcohol light yellowish brown with scattered irregular brown blotches of variable size, the most conspicuous in 3 rows: one below base of dorsal fin, one following lateral line, and one just above anal fin; blind side uniform light yellowish brown; fins pale with a few faint small brown spots basally in dorsal and anal fins.

Colour of ocular side of holotype when fresh: light brown with small irregular pale and dark brown blotches; scale edges dark brown to black; large irregular blackish blotches containing small pale spots in 3 rows, dorsal, ventral, and along lateral line; lateral line clearly evident as a broken black line; posterior edge of operculum broadly white; eyes pale with radiating dark lines on dorsal half of iris; scaled basal part of fins coloured like body; remaining part of fins pale with small dark blotches and a few larger ones along base.

Etymology. Named lateralis from the Latin word with the same meaning in English, in reference to the distinct pigmented lateral line in life.

Remarks. The holotype was collected from rock and sand bottom of a protected bay, but the habitat of the smallest paratype was unexpected. It was taken from a steep rocky slope with no obvious sand during the day. Species of Aseraggodes are typically found on sedimentary bottoms, at least by day, and they are usually buried during daylight hours.

The smallest paratype of Aseraggodes lateralis is in poor condition with the fins badly eroded, a result of long retention in isopropanol of insufficient concentration. A comparison of the figures of the holotypes of Aseraggodes lateralis and A. cyclurus reveals similarity in body and fin morphology and in colour pattern. Both species have 37 vertebrae and nearly the same structure of the fins. Aseraggodes cyclurus differs in having higher dorsal, anal, and lateral-line scale counts (see Tables 1–3), extremely small cirri on the ventral edge of the head, and small slender tubercles instead of scales anteriorly on the blind side of the head.

The 37.7-mm paratype is a mature female. An x-ray revealed that it had eaten two gastropods with intact shells 1.7 and 1.9 mm long.

Figures

Figure 7. Holotype of Aseraggodes lateralis, BPBM 10992, 64.2 mm SL, Ua Huka, Marquesas Islands.