Nearly all of the white shrimp are taken at the 72-fathom stations, 

 so no comparison with depth zones is possible. There is, however, an evident 

 seasonal variation in size caused by the migration of juvenile white shrimp 

 from estuarine nursery areas to the offshore grounds. This is first evident 

 in September and again from December through January, after which an in- 

 crease in average size is evident until August. 



Day /night comparisons show a definite catch increase for brown 

 shrimp at night at all depths, while the greatest catches of white shrimp were 

 taken in day trawls. 



3 100- 

 < 



O 75- 



I 



IE 



111 



a. 



S 



3 



Comparisons of day and night catch per unit of fishing 

 effort for brown shrimp between Galveston, 

 Tex., and Cameron, La., in 1961. 



Based on the examination of 21, 466 shrimp of commercial impor- 

 tance, the sex ratios for both white and brown shrimp show a 1:1 relationship 

 which is relatively constant at all depths sampled. 



17 



