792 
Fishery Bulletin 96(4), 1 998 
Table 2 
Morphometric measurements (in mm) of grass rockfish, Sebastes rastrelliger. 
SL 
(mm) 
Snout-anus 
length 
Head 
length 
Snout 
length 
Eye 
diameter 
Body depth at 
pectoral-fin ray base 
Body depth 
at anus 
Pectoral fin 
length 
10.0 
6.4 
3.7 
1.2 
1.2 
2.9 
2.4 
1.7 
13.8 
7.9 
4.5 
1.5 
1.6 
3.4 
3.1 
2.9 
16.7 
8.4 
5.0 
1.7 
1.8 
3.8 
3.3 
3.4 
16.7 
8.4 
5.0 
1.7 
1.8 
3.8 
3.3 
3.4 
16.8 
8.9 
5.4 
1.8 
1.9 
3.8 
3.4 
3.4 
17.4 
10.2 
5.8 
2.1 
1.9 
3.9 
3.3 
3.6 
18.0 
10.5 
5.9 
2.2 
2.0 
4.3 
3.4 
3.8 
18.3 
10.5 
6.2 
2.2 
2.0 
4.3 
3.9 
3.7 
18.8 
10.8 
6.3 
2.3 
2.1 
4.5 
3.9 
3.8 
19.2 
10.9 
6.5 
2.4 
2.1 
4.6 
3.7 
4.0 
19.3 
11.1 
6.8 
2.5 
2.2 
4.6 
3.8 
4.2 
19.7 
11.4 
6.9 
2.5 
2.2 
4.8 
3.9 
4.3 
20.9 
11.7 
7.2 
2.7 
2.3 
5.1 
4.4 
4.5 
21.6 
12.8 
7.5 
2.9 
2.4 
5.9 
5.2 
4.8 
22.7 
13.7 
7.9 
3.0 
2.5 
6.2 
5.5 
5.2 
24.3 
14.0 
8.7 
2.5 
2.7 
6.7 
5.7 
5.8 
27.7 
15.9 
9.0 
2.6 
2.9 
7.6 
6.5 
6.7 
length of 18.3 mm. An unpigmented section was con- 
spicuous between the nape and cranial regions. Pig- 
ment on the flanks of the dorsal body intensified, 
especially in between the myomeres. Lateral mid- 
line pigment extended from the caudal peduncle to 
the gut cavity. Pigment on the lateral midline near 
the caudal peduncle coalesced into a large pigmented 
area, which decreased in intensity anteriorly. Much 
of the dorsal half of the operculum was covered with 
pigment. 
At 18.3 mm, the ventral half of the body remained 
mostly unpigmented, except for the presence of a 
series of melanophores on the ventral surface ante- 
rior to the gut cavity and between the branchiostegals 
(Fig. IE). Pigment at the anterior tip of the lower 
jaw remained similar in intensity to that of the 13.8- 
mm specimen. Postanal ventral midline pigment 
became reduced, especially at the base of the anal 
fin. Pigment was also absent between the ventral 
myomeres. 
By 21.6 mm, pigmentation increased over the en- 
tire body surface (Fig. IF). The dorsal midline pig- 
ment merged with the nape, head, snout, and ante- 
rior tip of the upper jaw pigment to form a solid line 
along the dorsal surface of the body from the mouth 
to the caudal fin. Pigment formed on the ventral half 
of the membranes of the spinous dorsal fin. Pigment 
increased around the ventral surface of the eye or- 
bit. Nape, head, and operculum pigment merged to 
form a vertical bar from the operculum to the dorsal 
midline, except for a small unpigmented area near 
the nuchal and parietal spines. Hypural pigment 
began to form, and the caudal peduncle became 
highly pigmented. The ventral surface of the body 
remained only lightly pigmented. A few pigment spots 
were observed at the base of the pelvic fin. 
Juvenile S. rastrelliger became highly pigmented 
throughout most of their body surface by 27.7 mm 
(Fig. 1G). The entire dorsal surface of the body was 
completely pigmented. Pigment also covered much 
of the ventral surface of the body. The gut cavity, the 
ventral surface of the head, and the area just above 
the anal fin still remained largely unpigmented. 
Some pigment was observed at the base of the pecto- 
ral fin. A line of light pigment occurred along the lat- 
eral midline. Hypural pigment became intense, but 
an area of decreased pigment was evident just ante- 
rior to the hypural area. The spinous and soft dorsal 
fins were highly pigmented, except for the membrane 
between spine 11 and 12 which was completely de- 
void of pigment. A few pigment spots occurred on the 
anal and caudal fins. 
Otolith examination 
A linear model provided a good fit for the relation- 
ship of total otolith radius versus SL (r 2 =0.94)(Fig. 
2). The growth rate of S. rastrelliger was estimated 
by a linear model fitted to the relationship of SL and 
age (coefficient of determination, r 2 =0.88)(Fig. 3). 
This model estimated a growth rate of 0.36 mm/day 
and an extrusion SL of 0. 15 mm. The extrusion check 
radius for S. rastrelliger ranged from 13.3 to 14.6 pm, 
averaging 14.0 pm (SD=0.39). Secondary primordia 
