jViacchi et a!.: Maternal effects on fecundity and egg quality of Merluccius hubbsi 
327 
Figure t 
Map of locations where samples of Argentine Hake ( Merluccius 
hubbsi) were collected during the peak spawning season (Janu- 
ary) of 2010 (black dots) and 2011 (squares) in waters off the 
province of Chubut in Argentina to examine maternal effects 
on the fecundity and egg quality. 
Nutritional status was determined by means of 2 
indices: 
1) the relative condition factor (Kn), expressed as a 
proportion between the observed GW and the GW 
determined by the relationship of TL versus GW, de- 
scribed by the following equation: 
GW = 0.0148 x TL 2 - 7634 (1) 
(coefficient of determination [r 2 ]=0.98, n=181, P<0.01) 
2) the HSI, which provides an indication of the status 
of energy reserves in the liver, defined by the follow- 
ing equation: 
HSI = ( LW l GW) * 100. (2) 
Ovaries collected were weighed to the nearest 0.1 
g after fixation, and a portion of each sample (about 
2.0 g) was removed from each gonad, dehydrated in 
ethanol, cleared in xylol, and embedded in paraffin. 
Sections of ovaries that were 5 pm thick were mount- 
ed and stained with Harris’s hematoxylin followed by 
eosin counterstain. Histological diagnosis was used to 
discard ovaries with evidence of recent spawning. 
Batch fecundity (BF), or the number of oocytes re- 
leased per spawning, and relative fecundity (RF), or the 
number of hydrated oocytes per gram of body weight, 
were estimated with the hydrated oocyte method on 
fixed ovarian samples (Hunter et al., 1985). Only ova- 
ries without evidence of recent spawning (no postovula- 
tory follicles) were selected (102 ovaries from samples 
collected in 2010 and 79 ovaries from samples collected 
in 2011). Three pieces of ovary, approximately 0. 1-0.2 
g each, were removed from the anterior, middle, and 
posterior parts of one gonad and weighed to the near- 
est 0.1 mg, and hydrated oocytes were counted. Batch 
fecundity for each female was the product of the mean 
number of hydrated oocytes per unit of weight and 
the total weight of the ovaries. Relative fecundity was 
determined as the batch fecundity divided by female 
weight (without ovary). 
