Toxicity responses of Artemia franciscano to the endocrine disrupter bisphenol A (BPA) were investigated. Exposure of Artemia nauplii (instar II-III) to BPA for 24 hrs and 48 hrs demonstrated LC50 values of 44.8 mg l(-1) and 34.7 mg l(-1), respectively. The length of nauplii was measured and compared with that of untreated animals. BPA exposed nauplii were significantly shorter than untreated individuals (24 hrs: 0.97 mm, 48 hrs: 1 mm) at a concentration range between 20 and 50 mg l(-1) (24 hrs: 0.9-0.7 mm, 48 hrs: 0.92-0.71 mm). Furthermore, the length of nauplii decreased as the dose of BPA increased for both 24 hrs and 48 hrs exposure periods. The results indicate that A. franciscana does not consist a highly sensitive test animal for the acute toxicity bioassays with BPA in comparison to other aquatic organisms. However, it becomes obvious that an inhibitory effect on growth of Artemia nauplii can be estimated within a short exposure period (24 hrs), even at doses lower than the median lethal concentration. The latter finding points out that A. franciscano may be an ideal model organism for further research on the physiological processes related to the inhibitory effect of BPA on the growth of crustaceans