Thalassiosira punctigera

General Close


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

Shape Coin-shaped
Size Diameter 40 - 186 μm, height 20 - 120 μm
Colour Yellow-brown
Connection Thin organic thread (if present)
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
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.


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).

Geographic Close


Widely distributed; occurring in many parts in the world.

Seasonal Common in low numbers during late spring and fall
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).

Information not available
Temperature Information not available


Thalassiosira angstii (Gran) Makarova 1970 Close


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.

Thalassiosira japonica Kisselev 1935 (heterotypic)
Ethmodiscus japonicus Castracane (heterotypic)
Coscinodiscus punctiger (Castracane) H. Peragallo 1889 (homotypic)
Ethmodiscus punctiger Castracane 1886 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).

, 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).

(Guiry and Guiry 2012)


Empire Eukaryota
Kingdom Chromista
Subkingdom Harosa
Infrakingdom Heterokonta
Phylum Ochrophyta
Subphylum Khakista
Class Coscinodiscophyceae
Subclass Coscinodiscophycidae
Order Thalassiosiranae
Family Thalassiosirales
Genus Thalassiosira
Species T. punctigera (Castracane) Hasle 1983

(Guiry and Guiry 2012)


Photosynthetic. Reproduces sexually and asexually (Guiry 2012).


Cells are usually solitary, though are sometimes in very short chains connected by a thin thread. The Close


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

surface is convex, with distinctive short, thick Close


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






A natural projection or appendage on an organism.

) widely distributed around the edge of the valve face (Hasle and Syvertsen 1997). Chloroplasts are numerous and small. The Close


(plural: nuclei) In eukaryotic cells, a membrane-bound organelle that contains the cell's genetic information; the nucleus controls the activities of the cell by controlling gene expression.

is central (Kraberg et al. 2010).
One 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 process
with external tubes is present near the valve Close


In diatoms, "the part of a valve that extends from the valve face, forming the valve edge." It is visible when the frustule is viewed in girdle view (Spaulding 2010).

(Horner 2002). There is one central Close

Strutted process

(how is this different than marginal process?) In some diatoms, a narrow tube through the frustule that is usually associated with the secretion of chitin. It may appear as a marginal process or as a simple pore in the valve wall (Spaulding et al. 2010).

strutted process
and a ring of small dense strutted processes with short external tubes located close to the Close


Features that provide support to other structures in the cell.

valve Close


The outline or border that defines the shape of an organism or cell.

. Valve Close


Often used to describe holes (areolae) on the valve surface of diatom frustules.

is in bundles (Hasle and Syvertsen 1997).


Diameter: 40 - 186 μm
Height: 20 - 120 μm
Valve mantle areolae: 10 - 23 in 10 μm

Marginal process

In some diatoms, a long, coarse external tube through the frustule (Tomas 1997).

Marginal processes
: 4 - 5 in 10 μm
(Hasle and Syvertsen 1997, Kraberg et al. 2010)

Similar species

Other Thalassiosira species. T. punctigera can be easily distinguished by its solitary nature and the short, thick spines around the valve margin.

Harmful effects

None known.


Neritic (Cupp 1943).


Cosmopolitan (Kraberg et al. 2010).
Occasionally present throughout the year, but more often during spring and early summer in Northern European seas (Kraberg et al. 2010). More abundant during winter and fall and very scarce in the summer in the European Atlantic (Gómez and Souissi 2010).
Common in low numbers during late spring and fall, rare during the summer.

Growth conditions

May be favoured by freshwater inputs (Kat 1982, cited in Gómez and Souissi 2010) and low temperatures (Gómez and Souissi 2010). May have a wide temperature and salinity tolerance (Dürselen and Rick 1999).

Environmental Ranges

Information not available.

Bloom characteristics

Information not available.


Cupp, E. E. 1943. Marine Plankton Diatoms of the West Coast of North America. University of California Press. Berkeley, California. 238.

Dürselen, C. D. and Rick, H. J. 1999. Spatial and temporal distribution of two new phytoplankton diatom species in the German Bight in the period 1988 and 1996. Sarsia. 84(5-6): 367-377. Gómez, F. and Souissi, S. 2010. The diatoms Odontella sinensis, Coscinodiscus wailesii and Thalassiosira punctigera in the European Atlantic: Recent introductions or overlooked in the past? Fresenius Environmental Bulletin. 19(8): 1424-1433.

Guiry, M. D. 2011. Thalassiosira punctigera (Castracane) Hasle, 1983. Accessed 19 Feb 2011.

Guiry, M. D. and Guiry, G. M. 2012. Thalassiosira punctigera (Castracane) Hasle. Accessed 19 Feb 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.

Kat, M. (1982) Effects of fluctuating salinities on development of Thalassiosira angstii, a diatom not observed before in the Dutch coastal area. J. Mar. Biol. Assoc. UK 62, 483-484. Kraberg, A., Baumann, M. and Durselen, C. D. 2010. Coastal Phytoplankton: Photo Guide for Northern European Seas. Verlag Dr. Friedrich Pfeil, Munchen, Germany. 204.

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