598 
Maturity and fecundity of arrowtooth 
flounder, Atheresthes stomias, 
from the Gulf of Alaska 
Mark Zimmer mann 
Alaska Fisheries Science Center, National Marine Fisheries Service 
7600 Sand Point Way NE 
Seattle, Washington 981 15-0070 
E-mail address. Mark.Zimmermann@noaa.gov 
Abstract. -Maturity and total fe- 
cundity are reported for arrowtooth 
flounder, Atheresthes stomias , from the 
Gulf of Alaska. Histological examina- 
tion of both ovarian and testicular tis- 
sues revealed that the maturity state 
of both sexes could not be determined 
reliably by macroscopic assessment. 
Maturity for females ranged from the 
early perinucleus to the migratory 
nucleus stage; none of the fish had 
postovulatory follicles or hydrated oo- 
cytes, indicating all samples were col- 
lected prior to the spawning season. 
Condition factor (CF), gonadosomatic 
index (GSI), and hepatosomatic index 
(HSI) increased significantly in the 
later stages of female development. 
Eyed-side ovarian lobes were signifi- 
cantly heavier than blind-side lobes, 
but oocyte size and density (oocytes/ 
gram) did not vary between lobes of the 
ovary or within the individual ovarian 
lobes. Total fecundity increased expo- 
nentially with length (F=0.0429 x 
L 4 °20) and linearly with somatic weight 
(F=350.4 xff- 138,482), with estimates 
ranging from 250,000 to 2,340,000 oo- 
cytes. Histological analysis of tissues 
indicated that females reach 50% ma- 
turity (L 50 ) at 47 cm, males at 42 cm. 
This estimate of male L 50 is probably 
high because no males in this study were 
ready to spawn, whereas a decrease in 
CF and an increase in GSI indicate body 
changes at a size of 30-35 cm. 
Manuscript accepted 16 December 1997 
Fishery Bulletin 95:598-611 (1997). 
Arrowtooth flounder, Atheresthes 
stomias, is a large piscivorous flat- 
fish with a range in U.S. waters 
from California (Allen and Smith, 
1988) through the Gulf of Alaska, 
the Aleutian Islands, and the east- 
ern Bering Sea. Although it is the 
most abundant groundfish in the 
Gulf of Alaska and is concentrated 
in relatively shallow waters (101- 
200 m, Martin and Clausen, 1995), 
arrowtooth flounder has experi- 
enced only limited commercial har- 
vesting. Arrowtooth flounder flesh 
softens soon after capture, possibly 
owing to an enzyme released from 
a myxosporean parasite (Greene 
and Babbitt, 1990), greatly reduc- 
ing its commercial value. Recent 
advances in food processing, how- 
ever, have allowed production of 
marketable quality arrowtooth 
flounder fillets (Greene and Babbitt, 
1990) and surimi (Wasson et al., 
1992; Porter et al., 1993; Reppond 
et al., 1993), which may stimulate 
further development of a fishery. 
Hunter and Macewicz (1985, a 
and b), Hunter et al. (1992), Mor- 
rison (1990), and others have care- 
fully examined many of the assump- 
tions of maturity and fecundity 
work and have provided histologi- 
cal details that made this project 
possible. Rickey’s (1995) research 
off the Washington coast has shown 
that arrowtooth flounders are group- 
synchronous batch spawners, and 
researchers generally agree on a fall 
or winter spawning period (Pert- 
seva-Ostroumova, 1961; Shunto v, 
1970; Fargo et al., 1981; Rickey, 
1995; Hosie and Barss 1 ). Studies on 
arrowtooth flounder have calcu- 
lated length at 50% maturity (L 50 ) 
for both males and females from 
different areas, but only by using 
macroscopic maturity assessment 
(Hosie and Barss 1 for Oregon; Fargo 
et al., 1981, for British Columbia, 
Canada; Rickey, 1995, for Washing- 
ton). Rickey (1995) included histo- 
logical analysis and descriptions of 
different maturity stages of ovarian 
tissues but did not use histological 
analysis for calculating L g0 and did 
not examine males histologically. 
No study has ever reported weight- 
based or length-based estimates of 
total fecundity (as defined in Hunter 
et al., 1992), nor have researchers 
examined possible differences in 
oocyte density or oocyte size be- 
tween or within ovarian lobes, 
which could bias total fecundity esti- 
mation. Researchers also have not 
reported changes in condition factor, 
gonadosomatic index, and hepa- 
tosomatic index with maturity stage; 
such information could provide use- 
ful information on development. 
In this study, I report on the ma- 
turity and total fecundity of arrow- 
tooth flounder in the Gulf of Alaska. 
1 Hosie, M. J., and W. H. Barss. 1977. Age 
and length at maturity of arrowtooth floun- 
der, Atheresthes stomias, in Oregon waters. 
Marine Field Laboratory, Oregon Dep. Fish 
and Wildlife, P.O. Box 5430, Charleston, 
OR 97420. Unpubl. manuscr., 9 p. 
