TURBIDITY RELATED TO SHRIMP SIZE IN TANKS WITH SOIL SUBSTRATE

Water turbidity was monitored daily during a 63-day growth trial with juvenile Penaeus vannamei in indoor laboratory tanks. The tanks contai ned a 2.5 cm layer of soil substrate collected from 14 ponds represent ing five shrimp farms in Texas. A linear regression model relating tur bidity to estimated shrimp length accounted for 49-83% of the total va riation in turbidity for the 14 soil groups. For averages of daily tur bidity and shrimp length over the 14 soil groups, the linear regressio n model yielded an r(2) = 0.92. Turbidity increased with shrimp length (75-135 mm), apparently because the elevated locomotory or feeding ac tivity of the larger shrimp increased the suspension of soil particles . These results suggest the potential of using water turbidity as a to ol for estimating shrimp biomass in ponds. (C) 1997 Elsevier Science B .V.