Propylene Phenoxetol as a Relaxant for the Pearl Oysters Pinctada imbricata and Pinctada albina

Abstract

The responses of pearl oysters Pinctada imbricata and Pinctada albina to the relax- ant, propylene phenoxetol (PP) were similar to those reported for other members of the genus. Wedges that keep the valves of oysters open were unnecessary as most values opened readily in the presence of PP (2 mL L-1 seawater). Relaxation generally occurred within 15 min and, upon removal from the relaxant bath, oysters recovered within 10 min without any sign of ill-effects. In general, both relaxation and subsequent recovery times decreased with increasing water temperature. The size of oysters had little effect on the time taken to open the valves in the presence of PP, the time to relax nor the time to recover after exposure. Prolonged exposure to PP (90 min) significantly increased the recovery time, but no mortality or apparent ill effects were observed in the week follow- ing exposure. Introduction