116 
Fishery Bulletin 106(2) 
Figure 3 
Sebastes melanostictus (blackspotted rockfish), UW 48464, 249.5 mm, male, Aleutian Islands, 
north of Islands of Four Mountains, 53.2207°N, 169.7395°W, 328 m depth, 2 June 2002. Photo by 
J. W. Orr. 
Discriminant function analysis 
Although the PCA produced overlapping species clusters 
of individuals identified and labeled separately from the 
analysis, the discriminant function analysis verified 
the a priori identification of nearly all individuals. The 
single linear discriminant function equation produced 
was highly significant (Wilks’s A=0.197, x 2 =222.772, 8 
df, P<0.0001): 
D = 101 . 557 (c? 1 ) + 52.453(s/iZ) 
+ 0.294(gr) + 5l.92(grl) + 0.564(cZr) 
- 38.604(p2rZ) - 22.601(d2Z>) - 10.203(paZ) - 10.445, 
where D = the discriminant score of an individual; 
dl = length of dorsal-fin spine 1 divided by SL; 
snl = snout length divided by SL; 
gr = number of gill rakers; 
grl = length of gill rakers divided by SL; 
Figure 4 
Underwater photo of Sebastes melanostictus (blackspotted rockfish) taken south 
of Kodiak Island, Alaska, ca. 56°N, 153°N, July 2005. Photo by D. Hanselman. 
dr = number of dorsal-fin 
rays; 
p2rl - length of pelvic-fin rays 
divided by SL; 
d2b - length of soft-dorsal-fin 
base; and 
pal - preanal length divided 
by SL. 
All but two individuals with 
negative scores had been previ- 
ously identified as S. aleutianus, 
whereas all but one individual 
with positive scores were S. 
melanostictus. The discrimi- 
nant function equation, there- 
fore, correctly classified 97.8% of 
individuals. The possible hybrid 
was classified correctly as S. 
aleutianus. The cross-validation 
procedure correctly classified 
97.1% of individuals. In addition 
to the three individuals above, 
one S. aleutianus was also mis- 
classified as S. melanostictus in 
cross validation. When using 
this equation for future species 
