The preparation of testate amoebae (Protozoa: Rhizopoda) samples from peat

The analysis of testate amoebae (Protozoa: Rhizopoda) in peat is proving to be a useful new quantitat ive technique for assessing hydrological change on peatlands. Preparation experiments were carried out on peat extracted from Coom Rigg Moss, Northumberland, England, in order to assess the impact of different procedures on the concentration and species composition of the faunas. Five replicates of each of six samples were treated by different techniques and the testate amoebae counted together with 200 Lycopodium spores. All preparation procedures suitable for pollen extraction reduce the number of tests recorded by up to 80% and the number of taxa recorded by 60%. KOH digestion did not destroy tests but damaged them, making identification difficult, although it enabled extraction of a higher number of tests. A simple water-based prep aration, with sieving to remove coarse and fine detritus, appears to give the best results and is an improvement on earlier techniques in removing more extraneous material from the samples. Testate amoebae counts from samples prepared for pollen analysis must be viewed with extreme caution and are unrepresentative of the faunal content of the peat in both absolute and relative terms.