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

Grooved shrimp, Penaeus aztecus and P. duorarum, reached peak abundance in the bay in April, May, June, August and November 1964. Three waves were detected. The first and largest wave appeared in early April. Cool water temperatures and decreasing salinities influenced a large-scale emigration of these shrimp in mid-May. The second wave appeared in early August, and left trawl stations in September. The third wave was detected in late October. This group was present in samples through December. Grooved shrimp were more abundant in summer and fall of 1964 than in 1963, but were less abundant during spring. A 46 per cent decrease in the overall trawl catch was observed in 1964. White shrimp, P. setiferus; were present in samples from June through November 1964. The major wave of white shrimp was detected in mid-June. These shrimp left the bay in mid-July, were greater in 1964 than in 1963.