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Fishery Bulletin 1 1 1 (4) 
a population level. In this sense, fecundity estimates 
by length class give information on the number of po- 
tential offspring that can be produced. Nevertheless, 
viability during the early life stages depends mainly 
on egg quality, which is associated with the quantity 
of nutrients stored in the oocytes (Brooks et al., 1997). 
Bromage et al. (1994) defined egg quality as “those 
characteristics of the egg that determine its capacity 
to survive.” There are different methods and indices 
that can be used to estimate the quality of fish eggs. 
Some of them are very simple, such as those techniques 
where morphometrical attributes (e.g., egg diameter or 
weight and size of the oil droplet) are used, and others 
are more complex, such as those where the biochemical 
composition (e.g., lipid or protein concentration) of the 
oocytes are used (Nocillado et al., 2000). 
Most studies have concluded that larger eggs are of 
better quality because they can produce larger larvae 
with higher survival rates (Hinckley, 1990; Rijnsdorp 
and Vingerhoed, 1994; Nissling et al., 1998; Trippel, 
1998). It is a general assumption that larger larvae 
may have advantages in finding food and in actively 
swimming through the water column that increase 
their probability of survival (Brooks et al., 1997; Al- 
varez Colombo et al., 2011). In contrast, in some stud- 
ies, no relationship between egg diameter and larval 
size was observed (Landaeta and Castro, 2012), or it 
was suggested that larger offspring could be more eas- 
ily detected by predators, and, therefore, large larval 
size would increase the risk of mortality (Kjesbu et 
al., 1996). However, in general, it is assumed that in- 
creased egg size leads to higher larval survival. 
Fish condition can be assessed through the use of 
different indices, on the basis of length :body-weight ra- 
tio (K) or liver-weight:body- weight ratio (hepatosomatic 
index [HSI] ) or on the basis of the biochemical com- 
position (e.g., lipids, proteins, or glycogen) of different 
tissues (Dominguez-Petit et al., 2010). It was observed 
that lipids play an important role as stored energy that 
can affect fecundity, oocyte quality, and larval viabil- 
ity (Wiegand, 1996; Lambert et al., 2003; Aristizabal, 
2007). Therefore, because the liver is generally the or- 
gan with the highest levels of lipid storage for gadoids, 
the HSI may be considered a good descriptor of female 
condition, and a strong influence on reproduction (Mar- 
shall et al., 1999; Marteinsdottir and Begg, 2002; Alon- 
so-Fernandez, 2011). 
Spawning of the Patagonian stock of the Argentine 
Hake occurs in waters off the province of Chubut in 
southern Argentina during spring and summer, and 
a main peak occurs between December and January 
(Macchi et al., 2007). This species is a batch spawner 
with indeterminate annual fecundity, meaning that un- 
yolked oocytes continuously mature and are spawned 
throughout the reproductive season (Macchi et al., 
2004). It has been reported that the size and age com- 
positions of Argentine Hake females in Patagonian wa- 
ters change during the spawning season, affecting egg 
production of this stock during this period (Macchi et 
al., 2004). Moreover, Macchi et al. (2006) found posi- 
tive relationships between oocyte dry weight (DW) and 
maternal variables, such as total length (TL) and age, 
relationships that could indicate a possible effect of fe- 
male size on egg quality. 
Although different aspects of reproductive biology 
of Argentine Hake have been studied in recent years 
(Macchi et al., 2004, 2005, 2006, 2007), information 
about the nutritional condition of spawning females in 
relation to reproductive potential is scarce. This infor- 
mation is essential for understanding the strategy of 
energy allocation during reproduction and for estimat- 
ing whether variations in size composition and feeding 
condition of spawning females could affect egg quality 
and, therefore, larval survival. Such information could 
improve the understanding of the recruitment varia- 
tions that have been observed in the Argentine Hake 
fishing stocks. 
The objective of this study was to determine which 
maternal features — length, weight, age, HSI, and con- 
dition — were correlated with which measures of egg 
quality and quantity — DW, oil globule size, and fecun- 
dity — in Argentine Hake from Patagonian waters. We 
also examined stomach fullness as a function of fish 
length to establish the relationship between feeding 
activity and the size of spawning females. 
Materials and methods 
Sample collection 
Samples of Argentine Hake were obtained from bottom 
trawls during 2 research surveys carried out in the 
north Patagonian area during January 2010 and 2011 
by the Instituto Nacional de Investigacion y Desarrol- 
lo Pesquero (INIDEP) (Fig. 1). Argentine Hake speci- 
mens were captured at depths between 50 and 110 m 
through employment of a bottom trawl with a mouth 
width of about 20 m, a height of about 4 m, and with 
a 20-mm mesh size at the inner lining of the codend. 
For histological analysis of ovaries, 192 mature fe- 
males near spawning condition (with hydrated oocytes 
after germinal vesicle breakdown) were sampled; ova- 
ries were removed and preserved (fixed) in 10% neu- 
trally buffered formalin. From each specimen, the fol- 
lowing measurements were recorded: TL in centimeters 
and total weight (TW), gutted weight (GW), and liver 
weight (LW) in grams. In addition, the sagittae oto- 
liths were collected for age determination. Ages were 
obtained through the use of the methods of Renzi and 
Perez (1992). 
Female condition and fecundity estimation 
Because fish weight may be greatly influenced by the 
stomach content and fullness of the gut, GW was used 
to estimate the condition of Argentine Hake females. 
