Development of a method to assess the ichthyotoxicity of the harmful marine microalgae Karenia spp. using gill cell cultures from red sea bream (Pagrus major )
- 272 Downloads
The present study reports the development of a method to investigate ichthyotoxicity of harmful marine microalgae using cultured red sea bream (Pagrus major) gill cells. The cultured gill cells formed adherent 1–2 layers on the bottom of the culture plate and could tolerate seawater exposure for 4 h without significant alteration in cell survival. The microalgae Karenia mikimotoi, Karenia papilionacea, K. papilionacea phylotype-I, and Heterosigma akashiwo were cultured, then directly exposed to gill cells. After K. mikimotoi and K. papilionacea phylotype-I exposure, live cell coverage was significantly lower than in the cells exposed to a seawater-based medium (control cells; P < 0.05). Toxicity of K. mikimotoi cells was weakened when cells were ruptured, and was almost inexistent when the algal cells were removed from the culture by filtration. Significant cytotoxicity was detected in the concentrated ruptured cells, and in the concentrated of ruptured cells after freezing and thawing though cytotoxicity was weakened; whereas, cytotoxicity almost disappeared after heat treatment. In addition, examination of the distribution of toxic substances from the ruptured cells showed that cytotoxicity mainly occurred in the fraction with the resuspended pellet after centrifugation at 3000×g.
KeywordsCytotoxicity Karenia mikimotoi Karenia papilionacea Marine fish gill cells
We are grateful to Dr. Shigeru Itakura (Fisheries Agency of Japan), Dr. Osamu Kurata (Nippon Veterinary and Life Science University), and Ms. Chiaki Hiramoto (National Research Institute of Fisheries and Environment of Inland Sea). This study was supported in part by a grant-in-aid from the Fisheries Agency of Japan.
- Dorantes-Aranda J, Seger A, Mardones J, Nichols P, Hallegraeff G (2015) Progress in understanding algal bloom-mediated fish kills: the role of superoxide radicals, phycotoxins and fatty acids. Plos one. doi: 10.1371/journal.pone.0133549
- Fisheries Agency (2013) Red Tides in the Seto Inland Sea. Fisheries Agency, Japan. http://www.jfa.maff.go.jp/setouti/akasio/gepou/pdf/24nenpou-1.pdf (in Japanese) Accessed 7 April 2017Google Scholar
- Hashimoto T, Suzuki Y, Sugimura M, Atoji Y (1987) Ultrastructure of gills and pseudobranches of red sea bream. Res Bull Fac Agr Gifu Univ 52:173–181 (in Japanese with English abstract)Google Scholar
- Mitchell S, Rodger H (2007) Pathology of wild and cultured fish affected by a Karenia mikimotoi bloom in Ireland, 2005. Bull Eur Ass Fish Pathol 27:39–42Google Scholar
- Pärt P, Norrgren L, Bergstrom E, Sjoberg P (1993) Primary cultures of epithelial cells from rainbow trout gills. J Exp Biol 175:219–232Google Scholar