Synonym(s)
*Sometimes referred to as C. didymum (Guiry 2012).
Classification
(Guiry and Guiry 2012)
Lifestyle
Description
Girdle
In diatoms, the portion of the cell wall between the two valves of a cell; made up of intercalary bands (bands closest to the valves) and connecting bands (bands in the middle of the girdle). In dinoflagellates, the equivalent of a cingulum or transverse furrow (Horner 2002).
girdle view, valves are concave with a distinct semi-circular protrusion in the centre, producing CloseAperture
"In some diatoms, the space between the valves of adjacent cells in chains" (Horner 2002).
apertures that are constricted in the middle. Spines are thin and arise from the corners of the cell, crossing near or away from the cell (Cupp 1943). Two large, plate-like chloroplasts are present, one in each valve, with a ClosePyrenoid
Any of various protein granules that can be found in the chloroplast of some algae species. It is associated with the production of starch.
pyrenoid in the protrusion (Kraberg et al. 2010).Labiate process
In diatoms, a simple slit in the valve wall with two internal lips, one on each side of the slit. They can be useful in identification because they are positioned differently in different species (Horner 2002).
labiate process is located in the centre (Kraberg et al. 2010).Measurements
Apical
(axis, spine) The region of the apex or point. Refers to the most anterior point or region of the cell (HPP 2003).
(apical axis): 10 - 40 μmLength Close
Pervalvar axis
The axis through the centre point of the two valves of a frustule. This axis is perpendicular to the valve face.
(pervalvar axis): 6 - 30 μm(Hasle and Syvertsen 1997, Kraberg et al. 2010)
Similar species
Harmful effects
Habitat
Distribution
Temperate to warm waters (Hasle and Syvertsen 1997).
Present throughout the year but with higher abundances in summer and fall in Northern European seas (Kraberg et al. 2010). Abundant during the summer off SW Spain (Establier et al. 1986).
Most abundant in late spring and late summer in Saanich Inlet (McQuoid and Hobson 1995). A common and abundant species off California (Cupp 1943).
Growth conditions
Photoperiod
The amount of time in a day that an organism is exposed to daylight. This varies between seasons, with photoperiods being longer in the summer and shorter in the winter.
photoperiods (McQuoid and Hobson 1995). N-limited conditions may trigger the formation of resting spores, and extended periods of darkness may contribute further to their development (Itakura et al. 1993). May be favoured by conditions of high N:P ratio (> 80; Yoshida et al. 1998).Environmental Ranges
Temperature range (°C): -1.462 - 29.468
Nitrate (μmol L-1): 0.056 - 34.037
Salinity: 30.119 - 35.801
Oxygen (mL L-1): 4.139 - 8.095
Phosphate (μmol L-1): 0.061 - 2.358
Close
Silicic acid
A general term to describe chemical compounds containing silicon, oxygen and hydrogen with a general formula of [SiOx(OH)4-2x]n. Diatoms polymerize silicic acid into biogenic silica to form their frustules (Azam and Chisholm 1976).
Silicate (μmol L-1): 0.754 - 92.735(OBIS 2012, cited in EOL 2012)
Bloom characteristics
References
Cupp, E. E. 1943. Marine Plankton Diatoms of the West Coast of North America. University of California Press. Berkeley, California. 238.
Encyclopedia of Life (EOL). 2012. Chaetoceros didymum. http://eol.org/pages/912053/overview. Accessed 28 Mar 2012.
Establier, R., Lubian, L. M. and Balsco, J. 1986. Phytoplankton and hydrography on the Bay of Cadiz (SW Spain) from March 1980 to December 1983. Investigación Pesquera (Barcelona). 50(1): 69-81.
Guiry, M. D. 2012. Chaetoceros didymus Ehrenberg, 1845. http://www.marinespecies.org/aphia.php?p=taxdetails&id=149122. Accessed 28 Mar 2012.
Guiry, M. D. and Guiry, G. M. 2012. Chaetoceros didymus Ehrenberg. http://www.algaebase.org/search/species/detail/?species_id=37421. Accessed 28 Mar 2012.
Hasle, G. R. and Syvertsen, E. E. 1997. Marine diatoms. In: Tomas, C. R. (ed.) Identifying Marine Phytoplankton. Academic Press, Inc., San Diego. 5-385.
Itakura, S., Yamaguchi, M. and Imai, I. 1993. Resting spore formation and germination of Chaetoceros didymus var. protuberans (Bacillariophyceae) in clonal culture. Nippon Suisan Gakkaishi. 59(5): 807-813.
Kraberg, A., Baumann, M. and Durselen, C. D. 2010. Coastal Phytoplankton: Photo Guide for Northern European Seas. Verlag Dr. Friedrich Pfeil, Munchen, Germany. 204.
McQuoid, M. R. and Hobson, L. A. 1995. Importance of resting stages in diatom seasonal succession. Journal of Phycology. 31(1): 44-50.
Ocean Biogeographic Information System (OBIS). 2012. Chaetoceros didymus. http://www.iobis.org/mapper/?taxon_id=419587. Accessed 28 Mar 2012.
Yoshida, Y., Mishima, Y. and Sato, M. 1998. Relationships between the dominant phytoplankton and DIN:DIP ratios in the inner part of Tokyo Bay. Nippon Suisan Gakkaishi. 64(2): 259-263.