strained by the Gulf V plankton net when taking each sample had to be esti- 

 mated by appropriate conversion of flowmeter readings. To this end, cal- 

 ibration factors for plankton net-flowmeter assemblies were computed fronn 

 data obtained expressly for this purpose. Sample counts of individuals com- 

 prising each (coded) larval type have been adjusted accordingly and tabulated. 

 Quantitative analysis is now underway. 



Sampling of postlarval penaeids twice weekly at a station inside 

 Galveston Entrance near the South Jetty terminated in May. These collec- 

 tions began in November 1959 and resvilted in 141 "standardized" samples 

 yielding more than 14, 000 postlarvae. During I960 postlarvae were found 

 from early January to mid-December with peaks in abundance occurring in 

 the periods mid- March to mid- April and mid-June to late August. None were 

 taken at this station between mid-December and mid-February. In contrast 

 to the large numbers of postlarvae taken during March and April I960 (9, 900 

 from 17 samples), relatively few (330 in 15 collections) were taken during 

 the same period in 1961. Analysis of these data and associated hydrographic 

 observations will begin shortly and should provide valuable knowledge regard- 

 ing movement of young commercial shrinnps into estuarine areas. 



One year of systematic plankton sampling in the Galveston Island 

 surf ended in April. Samples and hydrographic observations were secured 

 semiweekly at four equally spaced stations along the beach front. Penaeid 

 postlarvae occurred at these stations throughout the year and with about the 

 same frequency as those at the Galveston Entrance station. The question 

 arises as to whether the small (8-11 mm. total length) postlarvae found in 

 mid-January hatched during December or even earlier and, avoiding the un- 

 suited inshore waters, were spending the ensuing winter months in nearshore 

 waters in a state of reduced activity. 



13 



