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Fishery Bulletin 118(4) 
Table 5 
Transformed standard lengths (SLs) reported in the literature for Pacific hake (Merluccius productus), by source, sex, sea- 
son, region, and original type of length measurement (total length [TL], fork length [FL], or SL). Regions used in sources 
include Canada (CAN), Strait of Georgia (SG), Vancouver Island (VI), Washington (WA), Oregon (OR), California (CA), 
Baja California Sur (BCS), and the northern, central, and southern Gulf of California (NGC, CGC, and SGC). 
SL (cm) 
Range Season 
<62.3 CA 
<54.0 CAN, WA, OR, CA TL 
24.2-65.7 
9.5-61.3 
9.5-72.2 
9.5-59.5 
9.2—28.7 
Spring-summer 
Spring 
9.5-72.2 All SG 
37.7-63.6 
37.7-67.7 All VI 
37.7-59.5 
11.7-53.2 Spring 
- Winter 
7.5-33.5 All BCS 
32.5—40.7 
Summer 
Fall 
Winter 
10.4-81.5 Winter 
11.9-89.2 
11.9-89.2 
11.9-79.9 
Winter-spring 
Our results indicate that Pacific hake in the NGC pres- 
ent sex dimorphism because adult females had greater 
maximum lengths, weights, and allometric coefficients 
than males. These findings are similar to those of other 
studies that observed differences in size at age after sex- 
ual maturity (Dark, 1975; Mathews, 1975; Francis, 1983; 
Balart-Paez, 2005; King et al., 2012). Additionally, the 
maximum size that has been reported for Pacific hake was 
observed in the NGC in this study (Table 5). 
In all years except 2015, the allometric coefficient was 
lower than 3 but above the threshold of a 6 value of 2.5 
that Pauly (1984) and Froese et al. (2011) considered an 
indication of negative allometric growth. Furthermore, 
we did not find differences in the LWR between matu- 
rity stages, indicating that length and weight increase 
proportionally throughout the life of Pacific hake. In 
this regard, the variability of the allometric coefficient 
could be interpreted as seasonal growth in weight, as 
suggested by Bailey et al. (1982). They found that Pacific 
hake lose 5-10% of total weight during their spawning 
season (because of inanition) and gain 11-30% during 
Region type 
CA, OR, WA 
CGC-SGC 
15.9-88.1 All NGC 
WA, OR, CA 
WA, OR, CA 
Spring NGC 
Original 
length 
Source 
TL Best (1963) 
Alverson and Larkins (1969) 
Dark (1975) 
Mathews (1975) 
Mathews (1985) 
McFarlane and Beamish (1985) 
Beamish and McFarlane (1985) 
Stepanenko (1989) 
Saunders and McFarlane (1997) 
Balart-Paez (2005) 
Mazorra-Manzano et al. (2008) 
King et al. (2012) 
Godinez-Pérez (2016) 
This study 
their feeding season. Unfortunately, because all Pacific 
hake were sampled during winter (spawning season) and 
no stomachs were collected in our study, it was not pos- 
sible to provide evidence of seasonal changes in weight. 
Our data indicate that there was no effect of mesh size 
on mean SL. Homogeneity in mean SL can be explained 
by smaller individuals escaping because of the mesh 
size of nets and then, once the net becomes clogged with 
large individuals, selectivity of nets remaining constant. 
Likewise, the low abundance of fish in the size class of 
30-45 cm SL during 2015-2017 might be evidence of a 
size-dependent migratory pattern, ontogenetic differences 
in their spatial distribution, or interannual variability of 
abundance and distribution linked to environmental con- 
ditions (Agostini et al., 2008). 
Although these results shed light on the basic biology 
and fishery of the Pacific hake in the NGC, future studies 
should address management questions to foster sustain- 
able development. Although population characteristics, 
such as age structure, growth, maturity, and mortality, 
and fisheries ecology remain poorly understood for this 
