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Fishery Bulletin 113(4) 
dark coloration and its light band between the head 
bars that resembles a clerical collar (Goode, 1884; Jor- 
dan and Evermann, 1898). 
Distribution 
The true range of S. mystinus extends from central Or- 
egon to northern Baja California (specimens examined 
from 32.5°N to 44.5°N), with the highest concentra- 
tion of the species occurring off the coast of central to 
southern California (Fig. 9). Specimens examined were 
collected at depths of 0.5-30.0 m. Jordan and Gilbert 
(1881) originally described S. mystinus from specimens 
collected “off” San Francisco and Monterey, California. 
Subsequent observations cited the species as occurring 
from Baja California, Mexico, northward into British 
Columbia, and even Alaska (Love et ah, 2002). How- 
ever, it is apparent that all specimens examined from 
central Oregon northward into British Columbia are 
the new species, S. diaconus, and not S. mystinus. All 
purported specimens of S. mystinus from Alaskan wa- 
ters that we examined belong to other congeners, pri- 
marily S. ciliatus. 
Remarks 
Ten of the 11 surviving syntypes of S. mystinus are 
clearly conspecific and match the original description 
by Jordan and Gilbert (1881). However, USNM 27031 
is clearly not S. mystinus or S. diaconus, on the basis 
of substantial morphological differences. This specimen 
possesses an exceptionally long symphyseal knob and a 
maxilla extending almost to the posterior margin of the 
eye. In addition, its opercular spines are very well de- 
veloped and much longer than observed in any S. mys- 
tinus or S. diaconus specimens. This specimen lacks 
distinctive pigmentation, such as head bars or blotch- 
ing on the trunk; in fact it is entirely devoid of dark 
pigment. The other specimen originally in the same lot, 
ZMUC P791064 (ex-USNM 27031), is clearly recogniz- 
able as S. mystinus in that it lacks a symphyseal knob 
and bears a maxilla that extends posteriorly only to 
the vertical through the pupil of the eye. Additionally, 
it possesses faint head bars and blotching on the trunk. 
Given the major differences between USNM 27031 
and the remainder of the syntype series, it seems 
strange that Jordan and Gilbert (1881) would have con- 
flated them. An illustration of USNM 27031 published 
by Jordan and Evermann (1900: pi. 270, fig. 657; also 
see Mecklenburg et ah, 2002:360) may help explain the 
apparent lapse. The specimen currently designated as 
USNM 27031 does not correspond with the body shape 
or lower jaw shape of the illustration, and length of 
the specimen (402 mm TL, with significant caudal fin 
damage) far exceeds the measurement of 300 mm TL 
cited in the 1900 work. On the basis of the length of 
the specimen and the obvious shape difference, it is 
clear the current USNM 27031 is not the specimen 
originally designated by Jordan and Gilbert (1881) and 
illustrated by Jordan and Evermann (1900). 
It is unclear how the current specimen designated 
as USNM 27301 came to possess this number, but a 
note attached to USNM 27031 states “1 located Nov. 
21, 1946; some sent UZM Copenhagen 1881-7.” This 
note suggests that USNM 27031 was at one point lost 
and then relocated, presenting the possibility that the 
“relocated” specimen is not the original. The exact iden- 
tification of USNM 27031 remains unclear. If it was 
originally dark-colored (now faded), it is most likely ei- 
ther an elongated specimen or a poorly preserved spec- 
imen of S. melanops or S. ciliatus. However, the lack 
of pigmentation could also indicate that this rockfish 
was originally light colored, a supposition supported 
by the fact that all other members of the syntype se- 
ries retain some degree of dark coloration. If so, then 
the most likely species identification for this specimen 
is yellowtail rockfish Sebastes flavidus (Ayres, 1862). 
Either way, it undoubtedly does not represent S. mys- 
tinus, and we remove it from the paralectotype series. 
Comparisons of Sebastes mystinus, S. diaconus, and 
similar congeners 
Differentiation of the 2 species without the use of ge- 
netic techniques can be challenging, but the trunk col- 
oration provides the most obvious difference between 
the 2 species. Sebastes mystinus is generally lighter 
colored, gray-blue to green-blue, and has a blotched 
pattern on the body, whereas S. diaconus is generally 
darker, blue to blue-brown, and has a distinct speckling 
pattern on the trunk (Fig. 1A). The difference in trunk 
pattern is apparent in juvenile specimens; however, 
smaller juveniles (<100 mm SL) of both species are 
almost entirely brown-gray with only subtle evidence 
of trunk markings. Coloration patterns are visible, but 
faint, in some preserved material making this diag- 
nostic feature useful for historic specimens. Sebastes 
diaconus has a more pointed head and flat ventrum, 
as opposed to the generally rounded head and ventrum 
of S. mystinus. Sebastes diaconus specimens also have 
lower mean numbers of lateral-line pores (45 versus 48 
in S. mystinus). Although the range of values overlaps 
almost completely (41-51 in S. diaconus versus 42-52, 
Fig. 10); only 16% of S. diaconus specimens possess 
more than 47 pored lateral-line scales versus 69% in 
S. mystinus, and the differences are statistically sig- 
nificant (Student’s t-test: P=8.87x 10“ 6 ). 
Specimens over 150 mm SL differ between species 
in the prominence and average length of the symphy- 
seal knob, which measures 2. 6-5. 9% HL (4.6% HL) in 
S. mystinus and 4. 0-7.0% HL (5.9% HL) in S. diaconus 
(Fig. 6A). Many juvenile specimens of both species lack 
a distinctly developed symphyseal knob. Lower jaw 
length (9.1-12.3% SL [10.4% SL] versus 9.3-14.0% SL 
[11.1% SL] in S. diaconus) and overall HL (29.9-36.3% 
SL [33.2% SL] versus 30.3-39.7% SL [34.7% SL] in S. 
diaconus) are also higher in S. diaconus. The lower 
jaw of S. diaconus extends farther beyond the anterior 
margin of the upper jaw than it does in S. mystinus, 
and this length may increase allometrically in S. diaco- 
