Five Karenia species along the Chinese coast: With the description of a new species, Karenia hui sp. nov. (Kareniaceae, Dinophyta).

Dinoflagellates within the genus Karenia are well known for their potential to cause harmful algal blooms and induce detrimental ecological consequences. In this study, five Karenia species, Karenia longicanalis, Karenia papilionacea, Karenia mikimotoi, Karenia selliformis, and a new species, Karenia hui sp. nov., were isolated from Chinese coastal waters. The new species exhibits the typical characteristics of the genus Karenia, including a linear apical groove and butanoyl-oxyfucoxanthin as the major accessory pigment. It is distinguished from the other Karenia species by a wide-open sulcal intrusion onto the epicone, a conical epicone with an apical crest formed by the rim of the apical groove, and a hunchbacked hypocone. It is most closely related to Karenia cristata, with a genetic divergence of 3.16 % (22 bp out of 883 bp of LSU rDNA). Acute toxicity tests indicated that the five Karenia species from China are all toxic to marine medaka Oryzias melastigma. Karenia selliformis and K. hui were very toxic to O. melastigma, resulting in 100 % mortality within 4 h and 24 h, respectively. Further analysis by high-performance liquid chromatography revealed that four species, K. selliformis, K. longicanalis, K. papilionacea and K. mikimotoi were capable of producing Gymnodimine-A (GYM-A). The highest GYM-A content was in K. selliformis (strain HK-43), in which the value was 889 fg/cell. No GYM-A was detected in the new species K. hui, however and its toxin remains unknown. Below we provide a comprehensive report of the morphology, phylogeny, pigment composition, and toxicity profiles of Karenia species along the Chinese coast. These findings contribute new insights for monitoring of Karenia species, with important toxicological and ecological implications.

[Identification of ichthyotoxic microalgae species and its hemolytic activity by three-dimensional fluorescence spectra].

To identify ichthyotoxic microalgae species and its hemolytic activity by three-dimensional fluorescence spectra, the relationship between hemolytic activity and the three-dimensional fluorescence of typical ichthyotoxic algae (Karenia mikimotoi, Chattonella marina, Chattonella ovata) cultured in different Fe2+ concentrations was investigated with methods of Coif2 wavelet and Fisher discriminant analysis. The results showed that the differences of three-dimensional fluorescence spectra between ichthyotoxic algae and non-ichthyotoxic algae were within the 1 to 10 data points (wavelength lambda(em) = 650-680 nm) and 35 to 47 data points (wavelength lambda(em) = 725-750 nm, lambda(ex) = 400-425 nm). Fisher discriminant analysis showed that the correct discrimination ratios of ichthyotoxic algae and non-ichthyotoxic species are 91.7% and 100%, respectively, and the ratio of algae with medium hemolytic activity (> or = 10 HU, < 20 HU) was 70% and that of algae with low hemolytic activity (< 10 HU) and high hemolytic activity (> or = 20 HU) are both of above 80%.