Fig. 1. A time course study on the (A) pH and (B) concentration of ammonia of the ambient seawater at a specific position of the artificial burrow in which P. schlosseri was exposed. d, days. Values are means ± S.E.M. ^aSignificantly different from the corresponding 0 h values, P<0.05; ^bsignificantly different from the corresponding 3 h values, P<0.05; significantly different from the corresponding 0, 3 and 6 h values, P<0.05; significantly different from all the preceding values, P<0.05; ^*significantly different from values 0 h to 5 days, P<0.05.