528 
Fishery Bulletin 11 5(4) 
48 46 44 42 W 
Egg abundance 
+ no catch 
• 0.01 to 5 
® 5 to 50 
• 50 to 200 
• 200 to 350 
O 350 to 500 
O >500 
Figure 7 
Spatial distribution of abundance of eggs (eggs/m 2 ) of Argentine anchoita (En- 
graulis anchoita) sampled in the southeastern Brazilian Bight with ichthyo- 
plankton tows during 1975, 1988, 1990, 1991, and 1993. 
harengus ) in the North Atlantic (Blaxter and Hempel, 
1963). 
The regional variations in the egg size of Argentine 
anchoita were probably a result of the differences in 
the stocks analyzed, whereas the reasons behind these 
seasonal variations remain unknown. At least 2 possi¬ 
bilities exist that would explain the observed seasonal 
variation in egg size of Argentine anchoita: differences 
in the maternal stock (e.g., migration northward of 
larger adults during the winter) and abiotic variabil¬ 
ity (e.g., temperature variability). As noted above, fur¬ 
ther studies are necessary to confirm our hypotheses, 
including comparisons between the size composition of 
the adults of the different seasons and the different 
areas, as well as genetic studies. The information that 
the regional variability in egg size may be caused due 
to different aspects of the stocks analyzed may be use¬ 
ful for management purposes. 
Acknowledgments 
The authors thank those responsible for the Biologi¬ 
cal Collection “Prof. E. F. Nonato” (Oceanographic In¬ 
stitute, University of Sao Paulo) for the egg samples. 
The senior author is thankful for the scholarships giv¬ 
en by Fundagao de Amparo a Pesquisa do Estado de 
Sao Paulo. Comments and suggestions from J. Dias, S. 
Cadrin, and J. Muelbert improved the quality of the 
manuscript, for which the authors are grateful. 
