Synonym(s)
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)Actinoptychus undulatus (J. W. Bailey) Ralfs 1861 (heterotypic)
Actinocyclus undulatus Kützing 1844 (heterotypic)
Actinocyclus undulatus J. W. Bailey 1842 (heterotypic)
Actinocyclus senarius Ehrenberg 1838 Close
Basionym
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).
(basionym, CloseHomotypic
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).
homotypic)(Guiry and Guiry 2012)
Classification
(Guiry and Guiry 2012)
Lifestyle
Description
Valve
In diatoms, the structurally distinct halves of the cell wall (Becker 1996).
valve surface is divided into six CloseRadial
(symmetry) Describing a shape that many axes of symmetry. That is, it does not have a left and right like humans do (bilateral symmetry), but can be divided into equal halves no matter where you place the axis. Some examples of radially symmetrical organisms include sea stars and centric diatoms like Thalassiosira.
radial sectors, alternately raised and depressed, and visible as undulations in CloseGirdle
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. The central area is smooth and hexagonal; the rest is strongly CloseAreolated
Synonym: perforated. Describing a surface that has many holes. Often used to describe the valve surface of diatom frustules.
areolated (Cupp 1943). Chloroplasts are numerous and large (Hasle and Syvertsen 1997). Cells are yellow-brown in colour (Guiry 2012).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 near their margins (Horner 2002); the valve margin has numerous small CloseSpine
In some diatoms, "closed or solid structures projecting from the cell wall;" in dinoflagellates, solid projections that usually taper to a point.
spines (Cupp 1943). In raised sectors, CloseAreola(e)
In diatoms, the regularly repeated hexagonal holes on the valve walls (HPP 2003).
"areolae toward the outside of the cell [are arranged] in fairly regular parallel radial rows, toward the center [they are] irregular. ClosePunctum
(plural: puncta) A sharp tip or small point on any part of an organism's anatomy.
Puncta in more or less regular, crossing CloseOblique
At a slanted angle (i.e., not parallel or perpendicular).
oblique lines. The depressed sectors usually don't present CloseProcess
A natural projection or appendage on an organism.
processes, and in place of areolae only weakly marked dots that are bound together by a network of delicate lines. ClosePunctated
Marked with tiny coloured spots or depressions.
Punctation coarser, radial CloseStriae
(referring to pores in diatoms) In diatoms, a striation or row of pores on the valve face. "In centric diatoms, striae may be radial, running from the centre of the valve to the margin ... In pennate diatoms, striae may be parallel to the median line of the valve or raphe" (Horner 2002).
striation less striking, oblique rows stronger. Valve margin narrow, faintly striated" (Cupp 1943).Measurements
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): 10 - 70 μmAreolae: 4 - 7 in 10 μm
Puncta on raised sector: 16 - 18 in 10 μm
Puncta on depressed sector: 13 - 14 in 10 μm
(Cupp 1943, Hasle and Syvertsen 1997)
Similar species
Harmful effects
Habitat
Distribution
Cosmopolitan (Hasle and Syvertsen 1997), sometimes abundant in cold to temperate coasts (Kraberg et al. 2010).
Present throughout the year but slightly more abundant in winter and fall in Northern European waters (Kraberg et al. 2010). Irregular blooms from fall to early spring in the northwest coastal zone of Portugal (Resende et al. 2007). Abundant during the summer (wet season) in a Nigerian Close
Estuary
The area where a river meets the ocean. Often characterized by high sediments, high nutrient levels, salinity fluctuations and tidal mixing.
estuary (Essien et al. 2008).Present throughout the year, with higher abundances during spring and fall, and especially after strong water mixing events (e.g. storms).
Growth conditions
Environmental Ranges
Temperature range (°C): 0.657 - 29.468
Nitrate (μmol L-1): 0.056 - 32.386
Salinity: 31.144 - 36.252
Oxygen (mL L-1): 4.500 - 7.789
Phosphate (μmol L-1): 0.062 - 2.229
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): 1.191 - 90.016(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. Actinoptychus senarius. http://eol.org/pages/917712/overview. Accessed 07 Jan 2012.
Essien, J. P., Antai, S. P. and Benson, N. U. 2008. Microalgae biodiversity and biomass status in Qua Iboe Estuary mangrove swamp, Nigeria. Aquatic Ecology. 42: 71-81.
Guiry, M. D. 2012. Actinoptychus senarius (Ehrenberg) Ehrenberg, 1843. http://www.marinespecies.org/aphia.php?p=taxdetails&id=148948. Accessed 07 Jan 2012.
Guiry, M. D. and Guiry, G. M. 2012. Actinoptychus senarius (Ehrenberg) Ehrenberg. http://www.algaebase.org/search/species/detail/?species_id=31610. Accessed 07 Jan 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.
Horner, R. A. 2002. A Taxonomic Guide To Some Common Phytoplankton. Biopress Limited, Dorset Press, Dorchester, UK. 200.
Ishii, K., Ishikawa, A. and Imai, I. 2009. Marine diatoms emerged from in situ surface sediment in a temperate embayment. Phycologia. 48(4, suppl.): 48.
Kraberg, A., Baumann, M. and Durselen, C. D. 2010. Coastal Phytoplankton: Photo Guide for Northern European Seas. Verlag Dr. Friedrich Pfeil, Munchen, Germany. 204.
Ocean Biogeographic Information System (OBIS). 2012. Actinoptychus senarius. http://www.iobis.org/mapper/?taxon_id=398083. Accessed 07 Jan 2012.
Resende, P., Azeitero, U. M., Gonçalves, F. and Pereira, M. J. 2007. Distribution and ecological preferences of diatoms and dinoflagellates in the west Iberian Coastal zone (North Portugal). Acta Oecologica. 32(2): 224-235.