Study of the Juvenile Shrimp Populations of the Lower Laguna Madre - Study of the Texas Shrimp Populations

Grooved shrimp, Penaeus aztecus and P. duorarum, were present in samples from early April through December and were most abundant from April through May. The first and most abundant wave of shrimp occurred in early April. Smaller waves occurred during May, August, and September with continuous recruitment during most of the study period. A growth rate of 0.6 mm per day was indicated in the secondary bay area with shrimp leaving the secondary stations near 75 mm. A growth rate of about 1.3 mm per day was indicated in the tertiary area with shrimp leaving the station below 90 mm in length. The largest numbers of grooved shrimp occurred slightly earlier in 1963 than in 1962, but remained abundant for a shorter period of time. Averaged monthly samples showed a 40 percent decrease in numbers from 1962. White shrimp, P. setiferus, were taken from late May through December, and were most abundant from June through August. White shrimp were abundant only in shallow, muddy areas, and grew at approximately 1.7 mm per day in tertiary areas. Most shrimp left the bay when approximately 100 mm long. White shrimp were present in the bay during the same periods in 1962 and 1963, but were only 15 percent as abundant in 1963