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Chaetoceros decipiens/lorenzianus

Classification
General Close

Centric

(diatoms) Having radial symmetry, i.e., cell is shaped like a coin or a tuna can or a soup can.

Centric diatom
Description
Shape Elliptic cylinder
Size Large diameter 7 - 85 μm, length 9 - 35 μm
Colour Yellow-brown
Connection Touching of cell corners and fusing of adjacent Close

Spine

In some diatoms, "closed or solid structures projecting from the cell wall;" in dinoflagellates, solid projections that usually taper to a point.

spines
Covering Silica Close

Frustule

In diatoms, the hard and porous silica cell wall (Horner 2002).

frustule
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Flagellum

(plural: flagella) A tail-like projection that sticks out from the cell body and enables movement.

Flagella		 None
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Chloroplast

An organelle in the cell that contains the cell pigments (Horner 2002). This is where photosynthesis occurs. A chloroplast is a specialized chromatophore.

Chloroplast		 4 - 10, large, plate-like
Behaviour
Lifestyle Close

Photosynthesis

The chemical process by which light energy, water and carbon dioxide are combined to produce oxygen and organic compounds. Photoautotrophic organisms (plants and algae) use this reaction to produce their own food.

Photosynthetic. Sexual/asexual. Close

Resting spore

In diatoms, a cell that requires a dormancy period prior to germination and can survive for several years; usually developed to survive adverse conditions. They are commonly observed in centric but not pennate diatoms. The morphology of the spore may be similar or different from a vegetative cell; they usually have heavily silicified walls and are rich in storage products (Horner 2002).

Resting spores present
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Bloom

A rapid increase or accumulation of algal populations in an aquatic system. This will likely involve one or a few dominant phytoplankton species. This follows seasonal patterns (i.e., spring, summer or fall bloom) with dominant species being those that are best adapted to the environmental conditions of that time period. Discolouration of the water may be observed because of the algae's pigmentation. Blooms are often green but may be yellow-brown or red depending on the species present.

Bloom		 Information not available
Harmful effects None known
Distribution
Habitat Close

Neritic

Describing shallow, near-shore areas and the organisms that live there. Refers to shallow marine waters ranging from the low tide mark to the continental shelf. Varying amounts of sunlight penetrate the water, allowing photosynthesis by both phytoplankton and bottom-dwelling organisms. Close proximity to land favours high nutrient content and biological activity (Encyclopedia Britannica 2011).

Neritic
Geographic Close

Cosmopolitan

Widely distributed; occurring in many parts in the world.

Cosmopolitan
Seasonal Spring to summer
Growth Conditions
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Salinity

The dissolved ion content of a body of water. Can be measured in the following units: parts per thousand (PPT or ‰), practical salinity units (PSU), and absolute salinity (g/kg). PPT is measured by weight, denoting the number of parts salt per thousand total parts or a value of 10-3. PSU measures the conductivity of saltwater and compares it in a ratio to a standard KCl solution (because this is a ratio, salinity measured in this way can also be written without units). The newest unit of salinity is absolute salinity, which uses the mass fraction of salt in seawater (g salt per kg seawater) rather than its conductivity (TEOS-20 2010).

Salinity		 20 - 36
Temperature -2 - 29 °C

Synonym(s)

C. decipiens: Chaetoceros grunowii F. Schütt 1895 Close

Heterotypic

A difference in type. In naming species, a heterotypic synonym is one that comes into being when a taxon becomes part of a different taxon. Compare to homotypic.

(heterotypic)
C. lorenzianus: Chaetoceros cellulosus Launder 1864 (heterotypic)
(Guiry and Guiry 2012)
*C. lorenzianus is sometimes referred to as C. lorenzianum (Guiry 2012).

Classification

Empire Eukaryota
Kingdom Chromista
Subkingdom Harosa
Infrakingdom Heterokonta
Phylum Ochrophyta
Subphylum Khakista
Class Bacillariophyceae
Subclass Coscinodiscophycidae
Order Chaetocerotales
Family Chaetocerotaceae
Genus Chaetoceros
Species C. decipiens Cleve 1873
Species C. lorenzianus Grunow 1863

(Guiry and Guiry 2012)

Lifestyle

Photosynthetic. Reproduces sexually and asexually (Guiry 2012). Resting spores present for C. lorenzianus (Cupp 1943).

Description

Cells are connected in straight and stiff chains. Close

Valve

In diatoms, the structurally distinct halves of the cell wall (Becker 1996).

Valves are concave, with the corners directly in contact with adjacent cells. Spines arise from the corners and are usually fused with adjacent spines for a short distance before diverging. Close

Aperture

"In some diatoms, the space between the valves of adjacent cells in chains" (Horner 2002).

Apertures range from narrow to Close

Ovoid

Oval or egg-shaped.

ovoid. Chloroplasts are numerous (4 - 10), large, and plate-like (Cupp 1943). Cells are yellow-brown in colour.
Resting spore of C. lorenzianus has a primary valve with two protrusions, each of which possess branching extensions and a secondary valve that is smooth with a single hump (Cupp 1943).

Measurements

Large diameter Close

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): 7 - 85 μm
Length 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): 9 - 35 μm
(Hasle and Syvertsen 1997, Kraberg et al. 2010)

Similar species

None.

Harmful effects

None known.

Habitat

C. decipiens is oceanic, while C. lorenzianus is neritic (Cupp 1943).

Distribution

Geographic:
C. decipiens is cosmopolitan, while C. lorenzianus is found in temperate waters (Hasle and Syvertsen 1997).
Seasonal:
C. decipiens occurs mainly during spring in Northern European seas (Kraberg et al. 2010). C. lorenzianus can be abundant during winter and spring in the East China Sea (Luo et al. 2007) and during winter in coastal lagoons in Florida (Badylak and Philips 2004).
Local:
C. decipiens is usually abundant from early spring to early summer, and C. lorenzianus is common off California (Cupp 1943).

Growth conditions

C. lorenzianus can tolerate a wide temperate range from 12 to 28 °C (Luo et al. 2007).

Environmental Ranges

Depth range (m): 0 - 470
Temperature range (°C): -1.899 - 29.468
Nitrate (μmol L-1): 0.053 - 28.280
Salinity: 19.590 - 36.252
Oxygen (mL L-1): 4.444 - 9.192
Phosphate (μmol L-1): 0.046 - 2.337
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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): 0.687 - 59.039
(OBIS 2012, cited in EOL 2012)

Bloom characteristics

Information not available.

References

Badylak, S. and Philips, E. J. 2004. Spatial and temporal patterns of phytoplankton composition in a subtropical coastal lagoon, the Indian River Lagoon, Florida, USA. Journal of Plankton Research. 26(10): 1229-1247.

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. http://eol.org/pages/12010/overview. Accessed 31 Mar 2012.

Guiry, M. D. 2012. Chaetoceros Ehrenberg, 1844. http://www.marinespecies.org/aphia.php?p=taxdetails&id=148985. Accessed 31 Mar 2012.

Guiry, M. D. and Guiry, G. M. 2012. Chaetoceros Ehrenberg, 1844: 198. http://www.algaebase.org/search/genus/detail/?genus_id=43689. Accessed 31 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.

Kraberg, A., Baumann, M. and Durselen, C. D. 2010. Coastal Phytoplankton: Photo Guide for Northern European Seas. Verlag Dr. Friedrich Pfeil, Munchen, Germany. 204.

Luo, M. B., Lu. J. J., Wang, Y. L., Shen, X. Q. and Chao, M. 2007. Horizontal distribution and dominant species of phytoplankton in the East China Sea. Acta Ecologica Sinica/Shengtai Xuebao. 27(12): 5076-5085.

Ocean Biogeographic Information System (OBIS). 2012. Chaetoceros. http://www.iobis.org/mapper/?taxon_id=611649. Accessed 31 Mar 2012.