Photosynthetic pigments in the ciliate Laboea strobila from Long Island Sound, USA

Laboea sirobila Lohmann, a marine oligotrich ciliate, was presentin Long Island Sound, USA, from March through June 1984. Peakabundance occurred in mid-June, when it was estimated that 10.2x 10⁶ individuals m^–2 were present in the 37-m deep watercolumn. When preserved specimens were examined with epifluorescencemicroscopy, the photosynthetic pigments chlorophyll and phycoerythrinwere observed within chloroplasts inside the ciliate. Thesepigments were also present in Myrionecta (formerly Mesodinium)rubrum Jankowski, a photosynthetic ciliate which co-occurredwith L. strobila during the present study. Vertical profilesshowed both ciliates to be most abundant in the upper few metersof the water column, especially during periods of strong thermalstratification.