Mulloidichthys flavolineatus flavicaudus, Fernandez-Silva & Randall, 2016

Uiblein, Franz, Gouws, Gavin, Johnson, Jeffrey W., Lobel, Phillip S. & Shaheen, Shaker, 2020, Junior synonymy of Mulloides armatus and intraspecific comparisons of the yellowstripe goatfish Mulloidichthys flavolineatus (Mullidae) using a comprehensive alpha-taxonomy approach, Cybium 44 (2), pp. 137-155 : 151-152

Mulloidichthys flavolineatus flavicaudus (n = 29)

Paratypes (n = 5): CAS 237352 , 4 : 107-147 mm SL, and BPBM 41246, 102 mm SL, Red Sea , Saudi Arabia, Thuwal, 22°13’50”N, 39°01’43”E .

Non-types (n = 24). Red Sea: Israel, Gulf of Aqaba , Eilat : CAS 58876, 252 mm SL; CAS 206559, 146 mm SL; CAS 206715, 133 mm SL; CAS 206726, 198 mm SL; CAS 206736, 167 mm SL; SAIAB 4146 and 4160, 2, 126-152 mm SL, 29°33’S, 34°57’E ; SAIAB 65788, 3 , 91-100 mm SL, north beach; Egypt, Gulf of Suez: MNHN 1980-1504, 2 , 194-203 mm SL; N Red Sea , possibly Egypt: MNHN 1980- 1501, 177 mm SL, unknown locality “Kaded el hamden” (coll. Dollfus) ; MNHN 1980-1502, 159 mm SL, unknown locality “El had yayah” (coll. Dollfus); possibly Egypt or northern Sudan: MNHN A.3515, 2, 171-196 mm SL (coll. Botta); Sudan: HIFIRE 58445, 5 , 148-181 mm SL and HIFIRE 58446, 181 mm SL, Port Sudan, fish market; Saudi Arabia: RMNH 25004, 82 mm, Jeddah ; Eritrea: MNHN A. 3514, 136 mm SL, Massawa, 15°37’1”N, 39°28’1”E .

Diagnosis

First dorsal fin VIII, the first minute spine sometimes considerably reduced and/or hidden below skin and hence difficult to detect; pectoral fins 15-18; gill rakers 7-10 + 18-22 = 25-31; lateral-line scales 33-38; morphometric characters in adult fish (≥ 90 mm SL): body depth at first dorsal-fin origin 21–26; body depth at anus 16-22; caudal-peduncle depth 7.9-9.7; caudal-peduncle width 2.7-4.6; maximum head depth 18-22; head depth through eye 15-19; head length 27-33; snout length 12-16; orbit length 5.6-9.0; upper jaw length 8.2-10; barbel length 18-23; caudal-fin length 28-33; anal-fin height 12-16; pelvic-fin length 18-23; pectoral-fin length 18-23; pectoral-fin width 3.6-5.3; first dorsal-fin height 18-25; second dorsal-fin height 12-16; body silvery white, sometimes infused with yellow, darker above lateral line; head silvery white to yellowish, darker on dorsal part of snout and dorsally from mid-orbit; one straight yellow mid-lateral body stripe, its width subequal to pupil diameter frequently with a dark oval to rectangular blotch on yellow mid-lateral body stripe below first dorsal-fin base; stripe and/ or blotch sometimes only faintly or not visible due to colour changes, blotch often retained in preserved fish; dorsal and caudal fins whitish-grey or yellowish, pectoral, pelvic and anal fins pale whitish-grey or rose, partly transparent; barbels white; in preserved fish body generally pale brown to brown or ventrally pale and dorsally darkened; head pale brown to brown; fins uniformly pale-brown, partly hyaline.

Morphometric characters in juvenile fish (<90 mm SL): body depth at first dorsal-fin origin 19-23; body depth at anus 15-20; caudal-peduncle depth 7.7-9.0; caudal-peduncle width 2.7-3.8; maximum head depth 17-20; head depth through eye 13-17; head length 26-30; snout length 8.6-12; orbit length 6.6-9.0; upper jaw length 7.6-8.9; barbel length 14-21; caudal-fin length 26-31; anal-fin height 13-16; pelvic-fin length 19-23; pectoral-fin length 16-21; pectoral-fin width 3.4-4.2; first dorsal-fin height 18-22; second dorsal-fin height 13-15.

Meristic characters in subspecies: Mulloidichthys f. flavicaudus: First dorsal fin VIII, the first minute spine well detectable in 25% of adults; pectoral fins 15-17; gill rakers 7-9 + 18-20 = 25-29; lateral-line scales 33-35; M. f. flavolineatus: First dorsal fin VIII, the first minute spine well detectable in over 50% of adults; pectoral fins 15-18; gill rakers 7-10 + 19-22 = 26-31; lateral-line scales 34-38.

Distribution, size, depth and habitat

Mulloidichthys flavolineatus occurs in the Indian Ocean to Central Pacific: Red Sea , East and South Africa, Madagascar and Mascarenes east to the Hawaiian Islands , Line Islands and Pitcairn Group , north to southern Japan and Midway Islands, south to North West Cape (Western Australia), New South Wales ( Eastern Australia) at 36°S, Lord Howe Island , and New Caledonia, a single record from New Zealand (RMNH.PISC.11308). It attains at least 34 cm SL and occurs from close to the surface to 99 m depth, on or slightly above soft or hard bottoms, often on or in the vicinity of coral reefs.

Interspecific comparisons and differential diagnoses

Adult Mulloidichthys flavolineatus differs from all other congeners in a shallower body (e.g. body depth at dorsal-fin origin 21-26 vs. 25-30% SL; body depth at anal-fin origin 16-22 vs. 21-27% SL) and the frequent presence of a dark oval or rectangular blotch at mid-body below the first dorsal-fin base; in addition, it differs from M. ayliffe and M. mimicus in a shallower caudal peduncle (7.9-9.7 vs. 10-11% SL) and a single yellow vs. several yellow and bluish lateral body stripes; it differs from M. pfluegeri in fewer lateral line scales (mostly 33-37 vs. 38-39), in a narrower caudal peduncle (2.7-4.6 vs. 4.6-6.0% SL), shallower suborbital (8.0-12 vs. 12-14% SL), shorter jaws (upper-jaw length 8.2-10 vs. 11-12% SL), narrower pectoral fin (3.6-5.3 vs. 5.4-5.7% SL) and the presence of mid-lateral body stripe vs. absence; and it differs from M. vanicolensis in fewer gill rakers (gill rakers on lower limb 18-22 vs. 23-26; total gill rakers 25-31 vs. 31-35).

Juvenile M. flavolineatus differs from M. mimicus (a single 79 mm SL specimen examined by Uiblein, 2011) in a shallower body (e.g. body depth at dorsal-fin origin 19-23 vs. 24% SL; body depth at anal-fin origin 15-20 vs. 22% SL), shallower caudal peduncle (7.7-9.0 vs. 9.4% SL), longer upper jaw (7.6-8.9 vs. 9.3% SL), wider interdorsal distance (13-17 vs. 12% SL), shorter second dorsal-fin base (11-13 vs. 16% SL), shallower anal fin (13-16 vs. 17% SL), and shallower dorsal fins (first dorsal fin height 18-22 vs. 23% SL; second dorsal-fin height 13-15 vs. 16% SL). No other comparative data for juveniles of Mulloidichthys species are currently available.