Laura Guimaraes

Triops longicaudatus is a crustacean typically inhabiting temporary freshwater bodies in regions with a Mediterranean climate. These crustaceans are easily maintained in the laboratory and show a set of biological features that make them good candidates for diagnosing environmental quality and health. However, information about their responses to environmental contamination is scarce. This study characterised the locomotor responses of juvenile and adult/mature T. longicaudatus to low concentrations of five model toxicants upon a very short 1.5 h exposure: tributyltin, mercury, lindane, sodium hypochlorite and formaldehyde. A video-tracking system was used to record the locomotor behaviour. The data were analysed with an artificial neural network to identify distinct behaviours, followed by Chi-square and Correspondence analysis to characterise the response to each toxicant. The results showed that T. longicaudatus is sensitive to aquatic contamination, particularly sodium hypochlorite. Six behaviour types were defined, which allowed for the characterisation and discrimination of the test toxicants. The results support the need for more investigation into this species and its behaviour types as an alternative to animal testing and the more apical and often invasive endpoints commonly recommended in standard guidelines.