The Use of Artemia nauplii (Brine Shrimp Larvae) to Detect Toxic Compounds from Microalgal Cultures

Aqueous supernatants and methanol extracts of 80 freshwater microalgae, 190 marine microalgae and 118 cyanobacteria were screened for the presence of toxins based on their ability to kill laboratory cultured brine shrimp. Compounds toxic to brine shrimp were detected from 8 out of 190 (4.2%) marine algae, one out of 80 freshwater algae (1.3%) and two out of 118 cyanobacteria (1.7%) studied. Of the 11 algae giving positive results, 4 have previously been shown to produce toxins. A comparison of the brine shrimp assay and the isolated guinea-pig ileum assay, as a means of detecting bioactive compounds from algae, showed that 6 algae gave positive results in both assays, whereas 15 algae were positive only in the guinea-pig ileum assay and 5 algae were positive in the brine shrimp assay only. Both screens are therefore valuable in their own right.