Assessment of the potential of the anesthetic AQUI-S for live transportation of the southern rock lobster, Jasus edwardsii

Abstract

Lobsters are highly valuable species with large quantities now being transported live over great distances into international markets, where they often sell at more than US$100 kg–1. Lobsters experience mechanical and environmental stressors during the transport process, which initiate physiological responses that compromise their health and value of lobsters upon reaching market. AQUI-S, an aquatic anesthetic used in handling of live seafood, was evaluated for its potential for improving the transport of live lobsters. Using a non-invasive heart monitoring technique, the cardiac activity in the southern rock lobster, Jasus edwardsii (Hutton, 1875), was examined when exposed to varying concentrations of AQUI-S, and compared with standard transport procedures. The induction of varying levels of anesthesia with AQUI-S occurred quickly, within 10–20 min following immersion of lobsters in both low and high doses. However, significant suppression of cardiac activity was only achieved at high AQUI-S concentrations (>200 ppm), and the upper threshold for J. edwardsii is estimated to be 250 ppm. AQUI-S was rapidly cleared from lobsters and was associated with an increase in heart rate, especially in lobsters re-immersed in seawater. Overall, the results show that the administration of AQUI-S at low doses (i.e., 40 ppm) reduces stress during handling live J. edwardsii, while higher doses of up to 200 ppm will induce deeper anesthesia, which may also provide some residual benefit during the continued emersion of lobsters. However, the rapid clearance of AQUI-S by lobsters restricts the potential for maintaining longer-term benefits from sensory and metabolic suppression during extended live transport.