Observations on the morphology and ecology of Blepharisma lateritium ( Ehrenberg, 1831) Kahl, 1932

Abstract

Blepharisma species are not easily found in the nature and ecological field studies have not yet been performed ( Giese 1973), In Denmark Blepharisma lateritium was first collected by O. F. Müller in the winter 1777/78 and described Glødspilleren 1783, later, 1786 named Trichoda ignita. The organism has not been re found here until 1975 where the author repeatedly collected it in 4 out of 12 ponds or lakes. In 1978 a study was undertaken to determine its seasonal occurrence in an eutrophic pond, where it previously had been observed several times. The number of organisms, collected as well from surface layers as from sediments, was counted weekly. The seasonal fluctuations of small algae (food organisms), temperature, p H and the contents of dissolved O 2 , CO 2 , NH 4 + and H 2 S were determined. For the morphological study the organisms were either observed in vivo or fixed and stained. The field observations showed, that B. lateritium was present only during the winter and the early springtime, maximally in April. Cultures could be maintained only refrigerated (5 °C) and, although the organisms had the same conditions throughout a season, they seemed to display winter-spring maxima like the field organisms. Although B. lateritium is the Blepharisma species first mentioned in the ciliate literature, the present study seems to be the first to demonstrate its morphology by photomicrographs and to report adequate details on its ecology and of its maintenance in laboratory cultures.