Study of the Post-larval Penaeid Shrimp Entering Aransas Bay - Study of Texas Shrimp Populations

The first post-larval penaeids were taken in the Aransas Ship Channel bottom sample on February 19 at a depth of 8 mm, but not until after March 17 in mid-water channel and sand flat samples. They were most abundant in March and April. Sizes ranged from 6 to 14 millimeters. When shrimp Penaeus sp., were first taken in 1963, channel bottowm temperatures were 11.7 degrees C as compared to 15.8 degrees C at the same place and time in 1962. In 1963, 2.33 shrimp per unit effort were caught at that time; in 1962, 25.9 shrimp per unit effort were taken. After the middle of March, when post-larvae became abundant, temperatures were about 19 degrees C in both years. Associated organisms taken in large numbers were mysids, sergestids, crab larvae, and arrow worms. Mysids showed a spring abundance peak similar to penaeid post-larvae.