THE DISTRIBUTION OF TESTATE AMOEBAE (RHIZOPODA: TESTACEA) IN SOME FENS AND BOGS IN NORTHERN ENGLAND

Abstract

1. Eleven bog and fen areas (330 samples) in Northumberland, Westmorland and Lancashire were examined for testate Protozoa, providing a series of habitats with a pH range 3·2-7·0. 2. In fen conditions, above pH about 5·0, a group of 25 species occurred regularly and almost exclusively. The commonest species were Quadrula symmetrica, Cyphoderia ampulla, C. trochus var. amphoralis, Lesquereusia spiralis, Nebela collaris sensu stricto, N. lageniformis, N. penardiana, Euglypha rotunda, E. ciliata, Pontigulasia bigibbosa, N. tubulosa, N. galeata and Sphenoderia dentata. 3. In bog areas (pH 3·2-4·6), Amphitrema stenostoma, A. wrightianum, Difflugia bacillifera, D. bacillariarum, D. brevicolla, Nebela carinata and possibly Placocista spinosa were characteristic of pools. 4. In acid hummocks, wet areas were dominated by Amphitrema flavum and Hyalosphenia papilio, with Nebela tincta, Arcella catinus, N. militaris, Assulina muscorum, Heleopera rosea and Euglypha strigosa frequently present. Drier areas were dominated by N. tincta, Assulina muscorum, Arcella catinus, Heleopera sylvatica complex, Euglypha strigosa and N. militaris, with Trigonopyxis arcula and Bullinularia indica. 5. A number of species occurred over a wide range of habitats, but usually showed some ‘preference’ for either bog or fen conditions. 6. Fen areas contained more species (Mean 30·1) than areas with pH less than 5·0 (Mean 18·9). 7. The distribution of Testacea in northern England is similar to that recorded in other parts of Europe, but the types of association proposed by Harnisch (1927) are of only limited application.