Coolia are marine benthic dinoflagellates which are globally distributed and potentially toxic. This study provides the first investigation of species diversity and toxicity assessment of Coolia in Hong Kong waters. Fifty-one strains of four Coolia species, including C. malayensis, C. canariensis, C. tropicalis, and C. palmyrensis, were isolated from twelve sub-tidal habitats, and identified phylogenetically using 28S rDNA sequences. Exposure experiments (48-hour) demonstrated that the algal lysates extracted from the four Coolia species exhibited different toxic effects on the lethality and abnormality of two invertebrate larvae, i.e., brine shrimp Artemia franciscana and sea urchin Heliocidaris crassispina. Heliocidaris crassispina was more sensitive to the toxic effects of Coolia species than A. franciscana. Toxicity tests from both larvae revealed that C. malayensis was generally more toxic, and caused higher mortality rates when compared with the other three species. The emerging threat of harmful benthic dinoflagellates to marine environments and sensitive biota is discussed.
Bibliographical noteFunding Information:
This project was conducted at the State Key Laboratory in Marine Pollution and supported by the following funding sources: Collaborative Research Fund (C1012-15G to PKS Lam); Environment and Conservation Fund (Project 12/2012 to TC Wai); National Natural Science Foundation of China (41576113 to PTY Leung; and 41406184 to Meng YAN) and 2014 GD-HK TCFS Program via Innovation and Technology Commission of the Hong Kong SAR Government (GHP/016/14SZ to PTY Leung). The authors thank Zoe Ho, Teresa Ma, Jiarui Gu, Roy Lam and Michael Chiang (BCH, CityU) for their technique support. The authors also thank the anonymous reviewers for their useful comments and suggestions on the manuscript.
© 2017 Elsevier Ltd
- Benthic dinoflagellate
- Invertebrate bioassay
- Sea urchin
- Toxic algae