Effects of methyl bromide fumigation on anhydrobiotic micrometazoans

Anhydrobiotic organisms are well known for their resistance to extreme envi ronmental conditions while in the inactive, ametabolic, state. This study c onfirms that this resistance also transfers to treatments with the fumigant methyl bromide. Live specimens of nematodes, rotifers, and tardigrades wer e found after 70 h of treatment with methyl bromide. Quantitative estimates of survival in the eutardigrade Richtersitts coronifer revealed no differe nce between treated and untreated samples which had been kept dry for a sho rt time. However, R. coronifer from samples collected 11 months before trea tment had lower survival compared to samples collected shortly before the t reatment. The fact that anhydrobiotic organisms escape treatments with bioc ides should be considered a serious problem, both for the food industry and from the perspective of human-mediated spread of organisms. (C) 2001 Acade mic Press.