The static biossays were performed to determine lethal concentration (LC50) values of four heavy metals (Cd++, Cr+++. Cu++. and Zn++) of spotted brown shrimp (Penaeus brasiliensis) The test animals were collected from the Laguna of Restinga, Nueva Esparto, and were acclimated in the laboratory condition for 11-21 days. Temperature and salinity were 22 ºC and 36 ppt, respectively. The LC50 values (mg/l) determined by probability-logarithm transformation were as follows-cadmium: 38 (24 -h), 21 (48 -h), and 12 (60 -h);chromium:40 (48 -h), 23 (60 -h), 13 (86 -h), and 10 (96 -h); copper: 24 (48 -h), 19 (60 -h), 16 (72 -h), 14 (86 -h), and 10 (144 -h); and zinc: 69 (24 -h), 25 (36 -h), 15 (48 -h) and 8 (60 -h). The LC50 values of 48 -h and 60 -h indicate that the most toxic heavy metals to P. brasiliensis in order are zinc, cadmium, copper, and chromium.
