megan_smith's Favorites

Eucampia zodiacus Ehrenberg 1839

A live image of the marine diatom Eucampia zodiacus Ehrenberg 1839. Class, Mediophyceae; Subclass, Chaetocerotophycidae; Family, Hemiaulaceae. E. zodiacus is the type species for this genus (Guiry & Guiry 2021).

Girdle view. Only five species of Eucampia reported (Round et al., 1990, Guiry & Guiry 2021). Cells often form flattened chains by interlocking the two short apical elevations (horns). The wide apertures between valves may be elliptical, oval, angular elliptical to square in outline. Valves are concave between the two elevations. The labiate process (rimoportulae) is centrally located on the valve. Helical-spiral chains form due to small differences in growth of the valves and girdle. Chloroplasts are round to ovoid bodies (Hendey 1964, Hasle & Syvertsen 1996, Hoppenrath 2009).

Eucampia zodiacus is a cosmopolitan marine centric diatom species, not reported from polar regions. Frequently found in plankton samples from Trincomali Channel, Galiano Island, BC., Canada (Waters 1972, Shim, 1976)

Methods:

From marine plankton collected in the Trincomali Channel, Spanish Hill Wharf, North Galiano Island, Gulf Islands, British Columbia, Canada, May 15, 2021. Live sample. Nikon TE300, 40x DIC NA 0.90.

References:

Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 16 May 2021.

Hasle, G.R. & Syvertsen, E.E. (1996). Marine Diatoms. In: Identifying Marine Phytoplankton. (Tomas, C.R. Eds), pp. 173-176, Plate 35, p. 175. San Diego: Academic Press.

Hendey, N.I. (1964). An introductory account of the smaller algae of British coastal waters. Part V. Bacillariophyceae (diatoms). Her Majesty’s Stationary Office, London. pp. 107. Plate VII, fig. 1.

Hoppenrath, M., Elbrachter, M., Drebes, G. (2009) Marine Phytoplankton, Selected microphytoplankton species from the North Sea around Helgoland and Sylt. Schweizerbart’sche Verlagsbunchhandlung, Stuttgart, Germany. p. 98, Figs 42 j-q.

Round, F.E. Crawford, R.M. and Mann, D.G. (1990). The Diatoms, Biology & Morphology of the Genera, pp. 262-263. Cambridge University Press, Cambridge, UK.

Shim, J. H. (1976). Distribution and Taxonomy of Planktonic Marine Diatoms in the Strait of Georgia, B.C. Phd. Thesis, UBC. p. 152., p. 224 Plate II. Fig. 2.

Waters, R.E., Brown, L.N. and Robinson, M.G. (1972). Phytoplankton of Esquimalt Lagoon, British Columbia: Comparison with West Vancouver Island Coastal and Offshore Waters. Canadian Technical Report of Hydrography and Ocean Sciences. No. 37. Department of Fisheries and Oceans. p. 7, Table 2.

Mag. 400x
For comparison see http://www.digicodes.info/Micrasterias_furcata.html#2014039005.
A pond edge water sample (freshwater) was taken on 9/10/2021 using a 10 micron dip net to enrich for microorganisms.