The effects of temperature and salinity on the swimming ability of whiteleg shrimp, Litopenaeus vannamei

Swimming endurance of whiteleg shrimp, Litopenaeus vannamei exposed to various temperatures (15, 20, and 25 °C) and salinities (15, 32, and 40‰) was determined in a swimming channel against one of five flow velocities (5.41, 6.78, 8.21, 10.11, and 11.47 cm s− 1) for up to 9000 s. No shrimp swam the full 9000 s throughout the experiment. The swimming endurance decreased as swimming speed was increased at any of the temperatures and salinities tested and was significantly affected by temperature and salinity (P < 0.05). The power model (ν · tb = a) showed a better fit to the relationship between swimming endurance (t, in s) and swimming speed (ν, in cm s− 1) at any of the temperatures and salinities tested. The swimming ability index (SAI), defined as SAI=∫09000vdt×10−4(cm), was found to be temperature- and salinity-dependent in L. vannamei. The optimum temperature and salinity and corresponding maximum SAI were Topt = 21.3 °C and SAImax21.3 = 7.37 cm; Sopt = 27.6‰ and SAImax27.6 = 7.47 cm, respectively. The range of temperatures and salinities within which SAI is > 90% of the maximum was estimated between 17.6 and 24.9 °C and between 18.5 and 36.7‰, respectively. The results suggest that the power model fits well to the observed endurance estimates and the SAI is a good index to quantitatively describe the overall swimming ability of L. vannamei. Furthermore, temperature and salinity can limit the swimming performance of L. vannamei.