Fig. 4.

Time course of brevetoxin cell quota for K. brevis (Wilson clone) after hypoosmotic stress. Mean total brevetoxin for Wilson clone acclimated to salinities of 27 (black) and 35 (white) (reproduced from ref. 11) and after hypoosmotic stress (hatched, black and white). Brevetoxin extractions were performed within <3 h, 24 h, 6 d, 67 d, and 111 d after the salinity decrease. Brevetoxin cell quota increased rapidly within <3 h after hypoosmotic stress and reached a plateau after 24 h that continued to day 6, with a decrease noted at day 67. Error bars represent 1 SD (n = 6 for acclimated treatments; n = 4 for <3 h, 24 h, and 6 d; n = 3 for 67 d and 111 d). Differences among brevetoxin cell quotas were determined by ANOVA (P < 0.001). Bonferroni's post hoc t test determined no significant differences between treatments denoted by either a or b.