404 
PACIFIC SCIENCE, VoL IX, October, 1955 
Zebrasoma flavescens (Bennett) 
Fig. le; Fig. 7 
Acanthurus flavescens Bennett (1828: 41) 
(Oahu); Gunther (1873: 116, pi. 76, fig. 
B) (Hawaiian Islands); Steindachner (1901: 
493) (Honolulu). 
Zabrasoma agana Seale (1901: 110) (Guam). 
Zebrasoma flavescens Bryan and Herre (1903: 
134) (Marcus Island); Jordan and Ever- 
mann (1905: 397, pi. 59) (Oahu) ; Jordan 
and Seale (1906: 355); Jordan and Jordan 
(1922 : 66) (Hawaii) ; Fowler and Ball (1925 : 
19) (Johnston Island); Fowler (1928: 274, 
pi. 32, fig. A) (Hawaiian Islands, Johnston 
Island, Marcus Island); Aoyagi (in part) 
(1943: 203) (Riu Kiu Islands); Schultz and 
Woods in Schultz et al. (in part) (1953: 
641) (Bikini Atoll, Marshall Islands). 
Scopas flavescens Jenkins (1903: 480) (Hono- 
lulu and Puako Bay, Hawaii). 
Dorsal rays V (rarely IV), 23 to 26 (usually 
24 or 25); anal rays III, 19 to 22 (usually 20 
or 21); pectoral rays 14 to 16 (usually 15); 
anterior gill rakers 8 to 12 and posterior gill 
rakers 11 or 12 (based on a total of 12 spec- 
imens from the Hawaiian Islands, Johnston 
Island, Wake Island, Bikini Atoll, Marcus 
Island, and Guam); a 25 mm. transforming 
specimen from Saipan had 12 upper and 14 
lower teeth; a 77 mm. specimen collected by 
Schultz, Hiatt, and Brock at Bikini (U.S.N.M. 
No. 140586) had 15 upper teeth and 18 lower 
teeth; a 149 mm. specimen from Hawaii had 
18 upper and 22 lower teeth. 
The following proportional measurements 
were made on 15 specimens from 75 to 149 
mm. in standard length: length of longest 
dorsal ray 2.8 to 3.8 in standard length; length 
of fifth dorsal spine 2.95 to 4.0 in standard 
length; body depth 1.4 to 1.75 (2.4 in 26 mm. 
juvenile specimen); a well- developed dense 
patch of setae posteriorly on the side of the 
body, progressively more prominent in larger 
specimens. 
Color (in alcohol) uniform yellowish white, 
in life bright chrome yellow. Upper edge of 
Fig. 7. Zebrasoma flavescens (Bennett), 120 mm., 
Hawaiian Islands (reproduced from a 35 mm. Koda- 
chrome transparency). 
pectoral fin with a very narrow dark margin; 
sheath of caudal spine white. Preserved spec- 
imens often show a long, faint whitish pale 
band running backward and slightly down- 
ward from just behind the upper end of the 
gill opening. 
Two of three yellow specimens of Z. fla- 
vescens (U.S.N.M. No. 140567) collected by 
L. P. Schultz from Johnston Island are a light 
dusky color over the back and head and there 
is a slight concentration of brownish pigment 
anteriorly in the dorsal fin. The yellow Bikini 
specimen shows this same diffuse marking in 
the fin. Still, this is but a slight departure from 
the usual pure yellow color. 
This brightly-colored species is abundant 
in the Hawaiian Islands. Brock (1954: 302) 
calls attention to the interesting fact that it is 
much more common on leeward sides of 
islands than windward. His figure 1 shows 
the relative abundance of this fish (as Zebra- 
soma) in nine different localities around the 
islands of Hawaii and Oahu. 
Jordan and Evermann (1905: 398) believed 
Acanthurus virgatus Vaillant and Sauvage to 
be the young of Z. flavescens and placed it in 
the synonymy of the latter. A. virgatus had 
vertical dark bars on the body and was prob- 
ably a juvenile Zebrasoma veliferum. Juvenile 
