Favero et al: Variation in egg size of Engraulis anchoita in the southeastern Brazilian Bight 
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Seasonal variation 
Figure 1 
Maps of the study areas for our investigation of variation in egg size of Argentine an¬ 
choita (Engraulis anchoita): (upper right) area of the northern part of the southeastern 
Brazilian Bight sampled in 2001 and 2002 was used for the seasonal variation analy¬ 
ses, and (bottom) area of the nearly entire Southeastern Brazilian Bight sampled and 
divided into 3 areas, in 1975, 1988, 1990, 1991, and 1993, was used for the regional 
variation analyses. The 3 areas were those of Cape Frio to Sao Sebastiao Island (area 
1), Sao Sebastiao Island to Paranagua Bay (area 2), and Paranagua Bay to Cape Santa 
Marta Grande (area 3). 
mum depth possible, which did not exceed 200 m. If a 
sampling station was shallower than 60 m, the bongo 
net was lowered twice close to the bottom, increasing 
the volume of water filtered. Towing speed was about 
2.8-3.7 km/h. We analyzed only the samples from the 
0.333-mm mesh size net and that had been preserved 
at sea in 4% buffered formalin in seawater. All samples 
were archived in the Biological Collection “Prof. E. F. 
Nonato” (ColBIO) of the Oceanographic Institute, Uni¬ 
versity of Sao Paulo, Brazil. 
Eggs of Engraulidae were sorted on the basis of 
their ellipsoid shape, segmented yolk, and usually, ab¬ 
sence of oil droplets (Ciechomski, 1965; Phonlor, 1984) 
and then imaged by using a digital camera attached to 
a stereomicroscope. Their major and minor axes were 
measured from the photographs by using the image- 
analysis program ImageJ2 (Schindelin et al., 2015) and 
egg volume was calculated by following the method of 
Vanzolini (1977). Finally, eggs of Argentine anchoita 
were identified by their morphometric characteristics 
