The organism is a ciliate (rather than phytoplankton as commonly be seen in red tide). It can be distinguished by its two-lobed shape and the presence of many flagella in the middle of the body. Active swimmer under microscope : sometimes like jumping. However, massive amount of the species might also change the seawater into brick red, brown or rusty red. Red tide of Mesodinium rubrum normally occurs after the suddenly bloom of micro-algae.
Size of Specimen :
50 mm (L), 20 mm (diameter)
Distribution :
Widely distributed in the temperature, subtropical and tropical environments. Commonly be found in water samples of Tolo Harbour, Hong Kong and Dapeng Bay.
Major Limiting Factors :
Phytoplankton as feed.
Toxicity :
Non-toxic in nature. However, reports from Japan showed that symbiotic algae inside Mesodinium rubrum might be harmful to cultured fish and marine organisms.