The effect of vinegar on discharged nematocysts of Chironex fleckeri.

We are writing because we have serious concerns about the statistical analyses and data interpretation reported by Welfare, Little, Pereira, and Seymour. The authors state in the Abstract, “Part 1: There was a 69 +/32% (F = 77, P < 0.001) increase in venom discharge after vinegar was applied compared to post electrical stimulation.” The recovery of venom protein from a membrane after the application of vinegar subsequent to electrically stimulating tentacle cnidae to discharge, W4, was compared with protein recovered post stimulation in a saline wash, W3. Figure 2 shows W3 to be approximately 23 +/20%. While the authors imply the statistical difference between “venom discharge after vinegar was applied compared to post electrical stimulation”, or W4 vs W3, only the overall ANOVA signifi cance comparing all four treatments was quoted (F = 77, P < 0.001) and no statistical signifi cance was provided for this specifi c W4 vs W3 comparison. If we assume that standard errors of the means (SEMs) were used in Figure 2, a simple t-test will provide a P-value of only 0.11, comparing W4 and W3, an insignifi cant fi nding. The comparison of W4, post electrical stimulation to W1 the pre-stimulation control would yield a signifi cant value of P < 0.001 but this is hardly surprising and intuitively obvious.