788 
Description of pelagic larval 
and juvenile grass rockfish, 
Sebastes rastrelliger 
(family Scorpaenidae), 
with an examination of 
age and growth 
Thomas E. Laidig 
Keith M. Sakuma 
Tiburon Laboratory, Southwest Fisheries Science Center 
National Marine Fisheries Service 
Tiburon, California 94920 
E-mail address (forT E, Laidig): toml@tib.nmfs.gov 
Abstract.— Pigmentation patterns, 
meristic characters, morphometric 
measurements, and head spination 
were recorded and illustrated for the 
developmental series of larval and pe- 
lagic juvenile ( 10.0-27.7 mm SL) grass 
rockfish, Sebastes rastrelliger. Larvae 
were identified by the presence of 
strong dorsal and postanal ventral mid- 
line pigment and by the presence of pig- 
ment on the lateral midline. Juveniles 
became highly pigmented over most of 
their body and fin surfaces at a length 
of 27.7 mm. Pigment patterns were suf- 
ficiently distinct and consistent to dif- 
ferentiate larval and juvenile S. ras- 
trelliger from other Sebastes species 
occurring off central California. Otolith 
characters were also useful in identifi- 
cation of this species. Larval and juve- 
nile S. rastrelliger grew at a rate of 0.36 
mm/day, similar to the growth rates 
observed in other species of Sebastes. 
Manuscript accepted 11 February 1998 
Fish. Bull. 96:788-796 (1998). 
Rockfishes ( Sebastes spp.) support 
important commercial and recre- 
ational fisheries in the northeast- 
ern Pacific Ocean. During 1995, 
they accounted for approximately 
12.6% of the commercial groundfish 
catch in weight ( PFMC 1 ) and 19.4% 
of all species in the recreational 
landings off California, Oregon, and 
Washington (Witzig et al., 1992). 
Management of rockfishes has been 
difficult owing to the large number 
of species within this genus. Sixty- 
one species of rockfish are reported 
from California alone (Eschmeyer et 
ah, 1983). The need to identify and 
separate adult rockfish landed by 
the fishery has long been recognized 
(Phillips, 1964; Chen, 1971). Larvae 
and juveniles are far more difficult 
to differentiate than adults, but the 
need for their accurate identifica- 
tion is growing with their use in bio- 
mass estimates and recruitment 
studies (Moser and Butler, 1987; 
Hunter and Lo, 1993; Ralston et 
al. 2 ). Here we provide means to 
identify the larvae and juveniles of 
grass rockfish, S. rastrelliger. 
Sebastes rastrelliger is a thick- 
bodied, medium-size (maximum 
size, 56 cm), bottom-dwelling rock- 
fish that inhabits shallow, rocky 
areas (maximum depth, 46 m) from 
central Baja California to Yaquina 
Bay, Oregon (Eschmeyer et al., 
1983). This species accounts for less 
than 1% of the commercial ground- 
fish catch by weight (Pearson 3 ). 
However, in recent years landings 
have increased from 1.5 metric tons 
(t) in 1991 to 52 t in 1995. This may 
be attributed to a relatively new live 
fish fishery for this species in south- 
ern California (Love, 1996). Addi- 
tionally, Sebastes rastrelliger is also 
an important part of the nearshore 
recreational catch (Love, 1996). 
1 PFMC (Pacific Fishery Management 
Council). 1996. Status of the Pacific 
coast groundfish fishery through 1994 and 
recommended acceptable biological catches 
for 1997. Pacific Fishery Management 
Council, Portland, OR, 168 p. 
2 Ralston, S., J. R. Bence, M. B. Eldridge, 
and W. H. Lenarz. 1993. Estimating the 
spawning biomass of shortbelly rockfish 
( Sebastes jordani ) in the region of Pioneer 
and Ascension Canyons using a larval pro- 
duction method, 32 p. Southwest Fisher- 
ies Science Center, Natl. Mar. Fish. Serv., 
NOAA, 3150 Paradise Drive, Tiburon, CA 
94920. 
3 Pearson, D. E. 1994. Southwest Fish. 
Sci. Center, Natl. Mar. Fish. Serv., 3150 
Paradise Drive, Tiburon, CA, 94920. Per- 
sonal commun., 1997. 
