128 
Fishery Bulletin 106(2) 
Jordan and Evermann (1898), which is an error be- 
cause the four syntypes of S. aleutianus have a range 
of 30-32 gill rakers. In our material, the gill-raker 
count of 32 lies within the broad range of overlap in 
numbers of gill rakers in S. aleutianus and S. mela- 
nostictus (Table 5). Although the length of the second 
anal-fin spine is longer than in all other S. aleutia- 
nus of similar size, it is similar in size to the second 
anal-fin spine of all S. melanostictus. Interorbital 
widths of S. aleutianus and S. melanostictus differ 
slightly, and S. kawaradae has the wider interorbital 
of similar size S. melanostictus. Based on material 
examined from throughout the range of the species, 
all other morphometric and meristic data support 
the conclusion that S. kawaradae is a synonym of S. 
melanostictus. 
Examining specimens from the northeastern Gulf of 
Alaska, Gharrett et al. (2006) distinguished by mor- 
phological techniques more than 94% of specimens that 
had been earlier identified by genetic analyses. They 
found concordant results between allozyme data (Seeb, 
1986; Hawkins et al., 2005) and DNA markers (Ghar- 
rett et al., 2005). The results of our work, extending the 
morphological examination across nearly the entire geo- 
graphic range of both species, are very similar to theirs 
with a slightly higher degree of resolution. Detailed 
diagnostic color differences, as well as a combination 
of morphological characters, distinguish the two species 
(the dark “Type I” and light “Type II” of Gharrett et 
al., 2006). Most importantly, the persisting confusion 
between the light and dark “Types” is resolved. Most 
specimens of S. melanostictus (“Type I”) display an 
overall darker coloration than S. aleutianus (“Type II”), 
but this “darker” coloration may range from a dusky or 
blotched color pattern over the body to a few dark spots 
on a light background — a pattern that would presum- 
ably be called “light” by field biologists. In contrast, 
S. aleutianus is always pale and would invariably be 
described as light in the field. 
The length of the first dorsal-fin spine is of par- 
ticular importance in distinguishing between the two 
species. Gharrett et al. (2006) did not measure the 
first dorsal-fin spine length but found the “longest 
dorsal-fin spine” to differ significantly between the 
two species. Among our material, the length of the 
fourth dorsal-fin spine, which is most often the longest 
spine, is significantly different but does not differ con- 
sistently enough to be useful as a field character. In 
contrast, especially in field identifications when body 
color was equivocal, the length of the first dorsal-fin 
spine was particularly useful. Its heavy weighting 
in the discriminant function equation underlines its 
importance. 
Evidence of a low-level of hybridization between S. 
aleutianus and S. melanostictus has been found from 
analyses with allozyme data (Hawkins et al., 2005) and 
DNA markers (Gharrett et al., 2005). Both Hawkins et 
al. (2005) and Gharrett et al. (2005) found <1% of pos- 
sible hybrids in their large sample sizes. Although a few 
specimens have uncertain genotypes in our allozyme 
analysis, no individuals were determined conclusively 
to be hybrids with concepts of hybrid intermediacy, 
because the range of variation among all morphological 
characters overlapped to some degree between the two 
species. However, one individual (UW 116878, 236.0 
mm) from the northeastern Gulf of Alaska identified 
as S. aleutianus because of color and general morpho- 
logical features had the genetic signature of a possible 
hybrid and was also placed in the overlapping region 
of the PCA. It was captured with longline gear to- 
gether with specimens of S. melanostictus and other 
specimens of S. aleutianus at an intermediate depth 
of 300-400 m. 
Phenotypically, two species in the eastern North Pa- 
cific region are similar and often difficult to distinguish 
from S. aleutianus and S. melanostictus. Sebastes bo- 
realis is the deepest dwelling species of the genus and, 
like S. aleutianus and S. melanostictus, is a robust red 
rockfish. Until the work of Tsuyuki and Westrheim 
(1970) and Barsukov (1970), it was treated as S. aleu- 
tianus or S. melanostomus. It also may have up to two 
infraorbital spines and similar cranial spines, although 
the coronal spine is typically absent. Sebastes borealis 
is uniform reddish-pink, unlike S. melanostictus, which 
invariably has spots on its fins or body and is generally 
darker in color. At larger sizes, above about 40 cm TL, 
S. borealis can be distinguished by the length of its gill 
rakers, which are shorter, ca. 5-15% head length, and 
fewer (27-31) than the longer, ca. 10-20 % HL, and 
more numerous (29-36) gill rakers of both S. aleutianus 
and S. melanostictus. 
Sebastes melanostomus is readily distinguished un- 
derwater by color (Butler and Love, 2002), exhibiting 
distinct blotches of red and white, unlike either the 
uniformly pale S. aleutianus or distinctly spotted S. 
melanostictus. When captured and brought to the sur- 
face, it is similar to S. aleutianus in coloration, having 
a reddish-pink background coloration and some mot- 
tling, especially around the head and on the branchio- 
stegal membranes. It lacks the spotting on the body 
and fins of S. melanostictus and may be distinguished 
from both species by having only 1 or 2 infraorbital 
spines and usual absence of the coronal spine. 
Four species of western Pacific Sebastes are considered 
to be morphologically similar to S. aleutianus and S. 
melanostictus'. Sebastes matsubarai 1 Hilgendorf (1880), 
akodai; S. baramenuke (Wakiya, 1917), baramenuke; 
S. flammeus (Jordan and Starks, 1904), sankomenuke; 
and S. iracundus (Jordan and Starks, 1904), osaga. All 
are relatively large and robust reddish rockfishes that 
live at greater depths than do most other species. As 
a group they, including S. melanostictus, are referred 
1 As noted in editions of Eschmeyer (1998), the name Sebastes 
matsubarae Hilgendorf requires emendation to Sebastes 
matsubarai Hilgendorf because it was named for the male 
ichthyologist Shin-Nosuke Matsubara (Hilgendorf, 1880: 
footnote p. 14), a professor of the University of Tokyo 
and leader of an expedition in the waters around Japan 
in the mid-1800s, who also served as a translator for 
F. M. Hilgendorf (Abe, 1986). 
