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Fishery Bulletin 115(3) j 
Figure 1 
Locations where Argentine hake (Merluccius hubbsi) were collected during 
January for the years 2005 through 2013 in waters of the north Patagonian 
area off Argentina. Open circles indicate sampling locations in the area 
where Argentine hake typically spawn, and black squares indicate sampling 
locations in the nursery area for juvenile Argentine hake in the San Jorge 
Gulf. 
dehydrated in ethanol, cleared in xylol, and embedded 
in paraffin. From these gonads, 5-pm sections were 
mounted and stained with Harris hematoxylin followed 
by eosin counterstain. 
Estimation of length and age at maturity 
We constructed length- and age-based maturity ogives 
for female Argentine hake from samples and sub- 
samples collected during the summer spawning peak 
(January) of the Patagonian stock (Table 1). For esti- 
mation of L 50 and A 50 , the maximum likelihood method 
was used to fit the proportion of mature individuals by 
length class (TL) and age class to a logistic function 
(Kendall and Stuart, 1967). 
The presence of ovaries in fish classified in the rest- 
ing stage and collected during the main spawning peak 
of the Patagonian stock was taken as evidence of SS 
in female Argentine hake (Macchi et al., 2016). These 
gonads were characterized as having only oocytes in 
the primary growth phase and as having a thick ovar- 
ian tunica, with no evidence of ovary development or 
recent spawning (Rodgveller et al., 2016). Therefore, 
when considering SS in estimating the maturity ogives, 
we classified females in the resting stage as immature 
individuals. 
For this reason, and following the method of Rod- 
gveller et al. (2016), we estimated L 50 and A 50 on the 
basis of the following 2 interpretations of the matu- 
rity cycle: 1) the traditional interpretation, in which 
fish in the resting stage were classified as mature, and 
2) the revised interpretation, in which adult females 
classified as in the resting stage were considered to 
be functionally immature. We obtained coefficients of 
the maturity ogives by using both interpretations for 
each year during the period 2005-2013. The coefficients 
were compared by using an % 2 test according to Aubone 
and Wohler. 2 
In the case of the August surveys, we had only data 
for TL and gonad maturity stage from samples of fe- 
males collected in 2005, 2007, 2011, 2012 and 2013 (Ta- 
ble 1). Using this information, we constructed length- 
based maturity ogives for August of those years, and 
the models obtained were compared with the maturity 
ogives estimated using data from January of the same 
year, during the previous spawning peak. Coefficients 
of the logistic relationships obtained in both sampling 
seasons were compared by using an x 2 test. It was not 
possible to identify females that were skipping spawn- 
ing during August because the majority of the fish dur- 
ing this month were in a resting or immature stage. 
2 Aubone, A., and O. Wohler. 2000. Aplicacion del metodo 
de maxima verosimilitud a la estimation de parametros y 
comparacion de curvas de crecimiento de von Bertalanffy. 
INIDEP Inf. Tec. 37, 21 p. [Available from Institute Natio- 
nal de Investigation y Desarrollo Pesquero, Paseo Victoria 
Ocampo Nro. 1, B7602HSA Mar del Plata, Argentina.] 
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