Dinoflagellate cysts in recent marine sediments from SW India

During the period February-June 1996, dinoflagellate cysts were sampled and examined from surface sediments from two different estuaries and three dif ferent offshore sites around Mangalore, SW India. Forty-three different typ es of cysts were recorded in the sediment, of which 38 cysts belonged to th e orders Gonyaulacales, Gymnodinales and Peridiniales. Five cyst types coul d not be identified. Five types of cysts recorded belonged to the potential ly toxic genera of Alexandrium Halim emend. Balech and Gymnodinium Stein. T he toxic species Gymnodinium catenatum Graham was studied, for the first ti me, in Indian waters. The cyst flora from SW India is compared to earlier s tudies on cyst biodiversity and biogeography from the tropics. To our knowl edge this is the first study of dinoflagellate cysts in recent coastal sedi ments from Indian waters.