Abstract
Swimming ability is an important means for shrimp to survive in a water environment. To investigate the effects of different body lengths (L1: 6.5 ± 0.25 cm, L2: 8.8 ± 0.16 cm, and L3: 11.5 ± 0.28 cm) and different measurement methods on the measured critical swimming speeds (Ucrit), this study used experimental ecology methods to determine the Ucrit of three body length (BL) groups of whiteleg shrimp (Litopenaeus vannamei) at different time intervals (10, 20, 30, 40, and 50 min) and speed increments (1/2 BL s−1, 3/4 BL s−1, and BL s−1) in a biological swimming channel. The results showed that the time interval and speed increment significantly affected the Ucrit. In the small-body-length group (L1), the Ucrit of the shrimp decreased and then increased as the time interval increased, with no significant difference between time intervals or velocity increments. In the medium-body-length group (L2), at the speed increment of 1/2 BL s−1, the Ucrit of the shrimp under the time interval