New observations on the rarely reported tropical dinoflagellates Tripos lanceolatus and T. schroeteri from the Colombian Caribbean, South Pacific and Indian Oceans

Abstract We report the circumtropical dinoflagellate Tripos lanceolatus (Kofoid) F. Gómez from the Colombian Caribbean, provide a new record from the tropical western Pacific off Tonga, and the first record from the Australian sector of the Indian Ocean. We present the first scanning electron micrographs of thecal ornamentation and apical pore structure which show its morphological similarities to T. furca (Ehrenberg) F. Gómez within the subgenus Biceratium. We also report the more widely distributed tropical species T. schroeteri (B. Schröder) F. Gómez from the Colombian Caribbean, and compare it to the first scanning electron micrographs of the morphologically similar T. digitatus (F. Schütt) F. Gómez within the subgenus Archaeceratium.