Appearance of Dinophysis fortii following blooms of certain cryptophyte species

Abstract

We examined the possibility that dinoflagellates belonging to genus Dinophysis acquire plastids from certain species of cryptophytes. We measured the abundance of cryptophytes over a 3 yr period in Okkirai Bay, northern Japan by fluorescent in situ hybridization (FISH), using an oligonucleotide probe that specifically binds to the Dinophysis plastid small subunit ribosomal RNA. A high density of FISH-probed cryptophytes always occurred prior to peak occurrences of D. fortii, although the density of FISH-probed cryptophytes did not correlate well with the density of D. fortii. Although further investigation is needed, monitoring of these cryptophyte species may be useful for predicting Dinophysis growth and subsequent outbreaks of diarrhetic shellfish poisoning. © Inter-Research 2007.