Odontella aurita

General Close


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

Shape Elliptic cylinder
Size Large diameter 10 - 100 μm, height 15 - 80 μm
Colour Yellow-brown
Connection Mucous pads on Close


The apical or antapical extensions found in some armoured dinoflagellates; they contain cytoplasm, are covered in thecal plates and can be hollow or partially solid (Horner 2002).

Covering Silica Close


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



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



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

Numerous, small, elliptic, near valve walls
Lifestyle Close


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.

. 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 stage


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.

Information not available
Harmful effects None known
Habitat Close


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).

, Close


The ecological zone at the bottom of a body of water.

, and Close


Describing the part of an ocean, river, or lake that is close to the shore. This can also refer to the organisms that live there. The littoral zone includes everything from the high water mark to near-shore areas that are permanently underwater. There is no fixed distance from shore or water depth that defines the end of the littoral zone. See also Neritic, which is directly below littoral.

Geographic Close


Widely distributed; occurring in many parts in the world.

, most common in temperate regions
Seasonal Most abundant in winter and spring
Growth Conditions


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).

27.3 - 35.6
Temperature -1.5 - 6 °C (optimal)


Biddulphia aurita (Lyngbye) Brébisson 1838 Close


Expressing the same fundamental type or structure; may or may not be symmetrical (e.g., the two valves of a diatom, where they are the same shape and appearance, but one is bigger than the other). In naming species, a homotypic synonym is one that comes into being when a taxon gets a new name (without being added to an already existing taxon).

Diatoma aurita Lyngbye 1819 (homotypic Close


The original name for an organism. In botany, the original published nomenclature from which a new binomial nomenclature is derived for a particular group of organisms (Tindall 1999).

) (Guiry and Guiry 2011)


Empire Eukaryota
Kingdom Chromista
Subkingdom Harosa
Infrakingdom Heterokonta
Phylum Ochrophyta
Subphylum Khakista
Class Mediophyceae
Subclass Biddulphiophycidae
Order Triceratiales
Family Triceratiaceae
Genus Odontella
Species O. aurita (Lyngbye) Agardh 1832

(Guiry and Guiry 2011)


Photosynthetic. Reproduces sexually and asexually (Guiry 2011). Resting stage present (McQuoid and Hobson 1995).


Cells are connected in straight or zigzag chains. Close


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

are elliptical to Close


Lance-shaped. Having a wider rounded base and tapering towards the tip.

, each with two short and divergent horns that are inflated at the base. Adjacent cells are united by mucous pads on the end(s) of one or both of these horns. The centres of valves are convex but slightly flattened at the top, with zero to several short and divergent Close


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

(external tubes of Close

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 processes
; Cupp 1943, Horner 2002). Chloroplasts are numerous, small, kidney-shaped or elliptical and are located near the valve walls (Hasle and Syvertsen 1997, Kraberg et al. 2010). Cells are yellow-brown in colour (Guiry 2011).
The intercalary region is separated from the valves by a pronounced depression. The cell wall is heavily Close


Describing the character (i.e., white, shimmery) or chemical presence silicon dioxide (SiO2) as a component of phytoplankton cell covering.

(Cupp 1943). Horns have Close

Costate ocellus

"A plate of silica pierced by closely packed pores" with siliceous ribs between each row of pores (Tomas 1997).

(Hasle and Syvertsen 1997).


Large diameter Close


(axis, spine) The region of the apex or point. Refers to the most anterior point or region of the cell (HPP 2003).

axis): 10 - 100 μm
Small diameter Close

Transapical axis

In diatoms, the longitudinal axis of the valve.

(transapical axis
): 5 - 45 μm
Height 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
): 15 - 80 μm
Valve Close


In diatoms, the regularly repeated hexagonal holes on the valve walls (HPP 2003).

: 8 - 11 in 10 μm
Band areolae: 8 - 14 in 10 μm
(Hasle and Syvertsen 1997, Kraberg et al. 2010)

Similar species


Harmful effects

None known.


Neritic and littoral (Cupp 1943). Also benthic (Hendey 1964).


Cosmopolitan, with highest abundance in Arctic and Close


Relating to the area immediately south of the Arctic.

regions (Cupp 1943). Common temperate species (Horner 2002, Kraberg et al. 2010).
Much more abundant in late winter and spring than in summer or autumn in Northern European seas (Kraberg et al. 2010).
"Very common at Scotch Cap, Alaska, especially during April and May. Common off southern California but never in large numbers." (Cupp 1943).

Growth conditions

Extremely competitive under temperatures of -1.5 - 6 °C, which contributes to its dominance in winter/spring, although its optimal temperature in laboratory conditions is approximately 12 °C (Baars 1986). Higher temperatures (>6 °C) facilitate attachment to Close


Bottom surface. For example, the substrate can be rock, sand, mud, etc.

. Lower temperatures (∼0 °C) facilitate non-adherence behaviour. This may explain why it commonly occurs in benthic habitats during summer and autumn, and yet is common in the Close


Organisms that drift at the mercy of the currents.

during winter and spring (Baars 1986). Resting stage germination is most successful around 20 °C with a 16 h Close


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.

(McQuoid and Hobson 1995).

Environmental Ranges

Depth range (m): 0 - 70
Temperature range (°C): -0.934 - 24.625
Nitrate (μmol L-1): 0.360 - 24.783
Salinity: 27.251 - 35.625
Oxygen (mL L-1): 4.855 - 8.565
Phosphate (μmol L-1): 0.074 - 2.131

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).

(μmol L-1): 1.309 - 50.314
(OBIS 2011, cited in EOL 2011)

Bloom characteristics

Information not available.


Baars, J. W. M. 1986. Autecological investigations on marine diatoms. 4: Biddulphia aurita (Lyngd.) Brebisson et Godey. A succession of spring diatoms. Hydrobiological Bulletin. 19(2): 109-116.

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). 2011. Odontella aurita. http://eol.org/pages/911021/overview. Accessed 11 Nov 2011.

Guiry, M. D. 2011. Odontella aurita (Lyngbye) C. Agardh, 1832. http://www.marinespecies.org/aphia.php?p=taxdetails&id=149050. Accessed 05 Nov 2011.

Guiry, M. D. and Guiry, G. M. 2011. Odontella aurita (Lyngbye) C. Agardh. http://www.algaebase.org/search/species/detail/?species_id=39270. Accessed 05 Nov 2011.

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.

Hendey, N. I. 1964. An introductory account of the smaller algae of British coastal waters. Part 5: Bacillariophyceae (Diatom). In: Ministry of Agriculture, Fisheries and Food. Fishery Investigations Series IV. HMSO, London. 317.

Horner, R. A. 2002. A Taxonomic Guide To Some Common Phytoplankton. Biopress Limited, Dorset Press, Dorchester, UK. 200.

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). 2011. Odontella aurita. http://www.iobis.org/mapper/?taxon_id=753559. Accessed 11 Nov 2011.

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