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Dinophysis parva

Classification
General Dinoflagellate
Description
Shape Round, with a crown on top, a wing or fin at the side.
Size Length 22 - 30 μm, width 22 μm
Colour Reddish-brown with translucent areas
Connection None (solitary)
Covering Cellulose Close

Theca

(plural: thecae) Cell wall. In dinoflagellates, it is composed of cellulose plates within vesicles (Horner 2002).

theca
Close

Flagellum

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

Flagella		 Two Close

Transverse flagellum

In dinoflagellates, one of the two flagella they possess; responsible for the rotation of the cell around its length axis. The two flagella are directed parallel to one another and together, the rotational components result in a helical swimming path (Fenchel 2001).

(transverse and Close

Trailing flagellum

In dinoflagellates, one of two flagella they possess; responsible for the movement of the cell and due to its asymmetric arrangement it also causes a rotation of the cell around an axis perpendicular to the longitudinal axis. (Fenchel 2001).

trailing)
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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		 Present
Behaviour
Lifestyle Close

Mixotroph/mixotrophic

An organism that is both autotrophic (photosynthesizes or chemosynthesizes) and heterotrophic. That is, it can gain energy both from light (or chemical) energy and also by consuming other organisms. This allows such organisms to take advantage of different environmental conditions.

Mixotroph. Asexual.
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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		 No information available
Harmful effects May produce Close

Diarrhetic Shellfish Poisoning

(DSP) Mainly caused by okadaic acid, a toxin produced by some diatoms. When shellfish consume phytoplankton, they can bioconcentrate the toxin leading to non-life threatening symptoms that may include diarrhea, nausea, vomiting and cramps (Yasumoto et al. 1985).

diarrhetic shellfish poisoning (DSP)
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 Temperate coastal waters
Seasonal Late 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		 37 - 39
Temperature 16 - 20 °C

Synonym(s)

None.

Classification

Empire Eukaryota
Kingdom Protozoa
Subkingdom Biciliata
Infrakingdom Alveolata
Phylum Dinoflagellata
Class Dinophyceae
Subclass
Order Dinophysiales
Family Dinophyciaceae
Genus Dinophysis
Species D. parva Schiller 1933

(Guiry and Guiry 2011)

Lifestyle

Mixotrophic. Reproduces asexually by Close

Binary fission

A form of asexual reproduction where one cell divides into two identical cells. All prokaryotes and some eukaryotes reproduce in this manner. Compare with mitosis, where the nucleus must also divide, adding an extra step to the process.

binary fission (Smithsonian 2012).

Description

Cells are 22 μm wide and 22 μm long. Cells are subcircular and are rounded Close

Dorsal

Relating to the back portion of the cell; opposite to the ventral side.

dorsally (Horner 2002). The lower Close

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 list is wider than the upper (Horner 2002). Rows of Close

Poroid

A simple hole through the surface of a diatom valve (Smithsonian 2011).

poroids are visible on the theca (Horner 2002). Noticeable golden chloroplasts are present (Horner 2002).

Measurements

Length: 22 μm
Width: 22 μm
(Horner 2002)

Similar species

D. rotundata Claparede and Lachmann (Horner 2002). D. parva has chloroplasts while D. rotundata does not. D. rotundata is also larger than D. Parva (Horner 2002).

Harmful effects

May produce Close

Lipophilic

Having the ability to combine with or dissolve lipids.

lipophilic toxins Close

Okadoic acid

A polyether fatty acid that is produced by some species of dinoflagellates. The toxin responsible for Diarrhetic Shellfish Poisoning (DSP; Cohen et al. 1990).

(okadaic acid derivatives and Close

Pectenotoxins

(PTX) A group of polyether-lactone toxins that have been detected in microalgae in Australia, Japan, New Zealand and in a number of European countries. They are exclusively produced by Dinophysis species and can be found in filter-feeding bivalve molluscs (e.g., oysters or mussels). There are no reports of human illness causally associated with exposure to these toxins. Pectenotoxins co-occur with the okadaic acid group of toxins, which makes it difficult to assess whether the PTX-group toxins contribute to human cases of diarrhetic shellfish poisoning (DSP; EFSA 2009b).

pectenotoxins) causing diarrhetic shellfish poisoning (DSP).

Habitat

Neritic (Horner 2002).

Distribution

Temperate coastal waters (EOL 2011).

Growth conditions

No information available.

Environmental Ranges

Depth range (m): 1 - 75
Temperature range (°C): 15.927 - 19.935
Nitrate (μmol L-1): 0.307 - 1.078
Salinity: 37.924 - 39.077
Oxygen (mL L-1): 5.136 - 5.473
Phosphate (μmol L-1): 0.098 - 0.206
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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): 1.542 - 2.121
(EOL 2012)

Bloom characteristics

No information available.

References

Encyclopedia of Life (EOL) 2012. Dinophysis parva Schiller 1933. http://eol.org/pages/901370/overview. Accessed 30 April 2012.

Guiry, M. D. and Guiry, G. M. 2011. Dinophysis parva Schiller. http://www.algaebase.org. Accessed on 12 September 2011.

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

Smithsonian Institution 2012. Dinophysis fortii Pavillard 1923. http://botany.si.edu/references/dinoflag/Taxa/Dfortii.htm. Accessed 16 April 2012.