A DESCRIPTION OF OCCURRENCE AND MORPHOLOGY OF A NEW SPECIES OF RED-WATER FORMING STROMBIDIUM (SPIROTRICHEA, OLIGOTRICHIA)

We describe a red-water ciliate, Strombidium lingulum n. sp., collecte d from a marine fjord in British Columbia (BC), Canada. In August, 199 5, red-brown streaks were observed in the waters of Kyuquot Sound, BC. These streaks were composed of a ciliate population with an abundance in the surface of similar to 1.5 x 10(3) cells ml(-1). Density was re duced to < 50 cells ml(-1) below the surface. The bloom persisted for only a few hours; cells were observed for 3-4 days and were only occas ionally observed in the weeks after the bloom. The red waters were spe culated to be formed by a combination of downwelling events and an obs erved phototactic migration of the ciliate. As the ciliate was positiv ely phototactic and pigmented, it may be mixotrophic; it was certainly heterotrophic, as it contained dinoflagellates and small ciliates in food vacuoles. Ciliates were preserved in Lugol's iodine and then both protargol stained and prepared for scanning electron microscopy.