The Desmids of Lochaber
Received from Anne & Alastair Bruce. 1. August 2000
Sample from Sgurr, Choinnich, Beag, Lochaber. OS sheet 41, NN214 707.
Some samples contain thousands of specimens of just one species, others contain many different genera and species. This is a very good sample of the latter. Note Micrasterias oscitans (11) has semi-cells that are different from each other. Other specimens in the sample have both semi-cells like the left semi-cell in photo. I last recorded this from Thursley Common, Surrey. In 1986 & 1992. When I mentioned having found some at Thursley to Prof. A.Brook he asked if I had found Micrasterias jennerii in the same sample as they are often found together although it is not known why, I had not, although they are both found in this sample.
Actinotaenium cucurbitum. (1). L.60µm B.25µm.
Closterium directum. L.224µm. B.22µm
Cosmarium depressum var. planctonicum. C.ralfsii (4).
C.venustum (2). C.caelatum (3). C.quadrifarium.
Cylindrocystis brebissonii (6). L.75µm. B.21.5µm.
Euastrum cuneatum. E.insigne. (7). L.108µm B.51µm.
E.elegans. E.pinnatum (9). E.bidentatum. (10). E.crassum (5) note nodule on one semi-cell. E.ampullaeceum.
E.binale. (8). L.24µm B.24µm.
Micrasterias oscitans var. mucronata (11). M.jennerii. M.truncata.
Staurodesmus dejectus (12).
Staurastrum polymorphum. S.brachiatum. S.punctulatum. S.orbiculare var. depressum.
Tetmemorus granulatus. T.brebissonii
Figures in brackets refer to photomicrographs taking with a webcam some of which will be published later There are several more species not listed, more work needs to be done with the sample, it is difficult to determine some species unless more than one aspect of the specimen is seen.
An article on E.crassum with nodules was published in the QMC Bulletin Winter 1993 issue 22. An account of a bloom of a single species of the desmid genus Staurastrum appeared in MICROSCOPY the Journal of the QMC No.35. –1987. William Ells.