Trimyema shoalsia sp. n., an anaerobic, microaerotolerant marine ciliate from Appledore Island, Gulf of Maine, USA

A new species of Trimyema was discovered from a sediment sample from the intertidal zone of Appledore Island, Gulf of Maine, USA. Its morphology was studied using live and protargol stained specimens. The new species is the smallest reported, measuring 13.4-23.7 x 9.3-17.5 mu m, and has the fewest somatic kineties (14-24). A characteristic grouping of kinetosomes, termed the epaulet, occurs on the right lateral dorsal surface or "shoulder" of the cell. The oral architecture is distinct from that reported for other species. This paper details the morphological characters that must be examined in order to provide thorough descriptions and ensure proper identifications of Trimyema species: cellular and macronuclear length and width, number of vestibulary ciliary rows, number of somatic spirals, length of vestibulum, distance between posterior end of body and posterior end of ciliary spirals, cell shape, number of somatic kineties, and position of epaulet.