Tripos fusus (Ehrenb. 1834) F. Gómez, comb. nov. (Gómez, F., 2013)

Also currently named Ceratium fusus (Ehrenberg) Dujardin 1841, as Guiry (2020) regard it a synonym of Tripos fusus (Ehrenberg) F.Gómez (2013).

Class, Dinophyceae; Subclass, Peridiniphycidae; Order, Gonyaulacales; Family, Ceratiaceae; Genus, Tripos

Light microscopic (LM) image of the dinoflagellate Tripos fusus.

Description: Elongated and spindle-shaped body. Both horns, apical and antapical, approximately equal length. Both horns are gradually tapering and the left horn slightly bent or straight. The right hypothecal horn is very small to an almost non-existent tooth-like form (Steidinger et al. 1997). Widest part of the cell is at the cingulum, medially located. Many yellow-brown chloroplasts. Cells are reported to be 300-600 µm long and 20-30 µm wide (Hoppenrath et al. 2009) and 200-300 µm long by 15-30 µm wide (Al-Kandari et al. 2009). Surface of cell has linear markings on the surface (Horner 2002, Steidinger et al. 1997). Bioluminescence reported. A cosmopolitan species, reported from tropical to temperate marine waters. Can form thick blooms, reported to be toxic (Guiry, 2012).

Methods: Collected by plankton net from Trincomali Channel, Spanish Hills Wharf, N 48º 56.141’, W 123º 30.706’, west side of Galiano Island, Southern Gulf Islands, British Columbia, Canada, November 19, 2008. Live image of the cell in a glass bottomed culture dish. Imaging with a Leitz Diavert inverted microscope and a Nikon CoolPix 4500 camera.

Many thanks to Dr. Mona Hoppenrath, then at the Dept. of Botany, University of British Columbia for confirming the species for these images and taxonomic discussions. Thank you Kiyo Okuda for the boat trips on Trincomali Channel.

References:

Al-Kandari, M., Al-Yamani, F.Y., Al-Rifaie, K. (2009). Marine Phytoplankton Atlas of Kuwait’s Waters. p. 161. plate 9C. Kuwait Institute for Scientific Research, Safat, Kuwait.

Dodge, J.D. (1982). Marine dinoflagellates of the British Isles. London: Her Majesty's Stationery Office.
Gómez, F. (2013). Reinstatement of the dinoflagellate genus Tripos to replace Neoceratium, marine species of Ceratium (Dinophyceae, Alveolata). CICIMAR Oceánides, 28(1): 1-22. 
Gómez, F., Moreira, D. & López-Garcia, P. (2010). Neoceratium gen. nov., a new genus for all marine species currently assigned to Ceratium (Dinophyceae). Protist 161: 35-54.
Hoppenrath, M., Elbrachter, M., Drebes, G. (2009) Marine Phytoplankton, Selected microphytoplankton species from the North Sea around Helgoland and Sylt. p.175. fig. 70. h-j. E. Schweizerbart’sche Verlagsbunchhandlung, Stuttgart, Germany.

Horner, R. (2002). A Taxonomic Guide to Some Common Marine Phytoplankton. Biopress Ltd. Bristol, UK.

M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2020. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 26 March 2020.

PLANKTON*NET data provider at the Alfred Wegener Institute for Polar and Marine Research, a World-wide electronic publication, searched June 2, 2012: http://planktonnet.awi.de/#content
Steidinger, K.A. in collaboration with Tangen, K. (1997). Dinoflagellates. In: Identifying Marine Phytoplankton. (Tomas, C.R. Eds). San Diego: Academic Press.