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Smithsonian National Museum of Natural History
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Ceratocorys horrida
apical:
In dinokonts, the anterior pole of the cell
antapical:
In dinokonts, the posterior pole of the cell
antapical plates:
In thecate dinokont species, the plates covering the posterior end of the cell (designated with '''') not in contact with the cingulum.
apical plates:
In thecate dinokont species, the thecal plates that surround and are in contact with the apex of the cell, designated with ', not in contact with the cingulum. In those species with an apical pore complex (APC), the plates that touch the APC.
apical pore plate (Po):
Part of the apical pore complex (APC); a feature located on the epitheca of many marine, armored thecate) dinokont species. The Po houses an apical pore (ap), and often times, small periferal pores. The Po can be long and narrow, as in Ostreopsis spp., or wide and triangular, as in Gambierdiscus spp.
armored:
Dinoflagellate species that have thecal plates of varying thickness and orientation in identifiable tabulation series. Often the plates are thickened or ornamented with reticulations, spines, grooves, etc., are often characteristic to a species.
benthic:
Occurring at the bottom of the water column.
bloom:
High concentrations of planktonic organisms due to enhanced cell division (growth) rates. Seasonal blooms are often related to periodical increase in nutrient and light conditions (e.g. spring bloom). Exceptional blooms are often dominated by one or a few species and may discolor the water a reddish-brown color, hence the name 'red tide'.
chloroplast:
Membrane-bound organelle found in the cytoplasm of various eukaryotic organisms that contain the chlorophyll pigments and the enzyme systems for photosynthesis.
ciguatera:
A human intoxication caused by ingestion of tropical piscivorous reef fishes contaminated with toxin-producing benthic/epiphytic dinoflagellates. These fish accumulate biotoxins through the food chain. More than 175 separate gastrointestinal, neurotoxic, or cardiovascular symptoms may be associated with this poisoning. In extreme cases death can result from respiratory failure. Although incidence is high, human mortality is low .
cingulum:
In dinokont species, this structure is usually a furrow (girdle) encircling the cell once or several times, and it can be displaced. In thecate species, the cingulum is made up of plates. This structure is missing in some type cells (e.g. Prorocentrum).
desmokont:
A dinoflagellate cell type in which two dissimilar flagella emerge from the anterior part of the cell; e.g. Prorocentrum sp. This morphological type does not have a cingulum or a sulcus.
Diarrhetic Shellfish Poisoning (DSP):
A human gastrointestinal disease caused by the ingestion of toxic marine shellfish (filter-feeding bivalves) from cold and warm temperate regions of the Atlantic and Pacific Oceans. Shellfish can accumulate and store large quantities of red tide dinoflagellate toxins without apparent harm to themselves . Symptoms include diarrhea, nausea and vomiting lasting a few days. No human deaths have been reported.
dinoflagellate:
Biflagellate unicellular alga member in the Phylum Pyrrhophyta.
dimorphic:
The occurrence of two different forms e.g. shape on the same organism.
dinokont:
A dinoflagellate cell type in which two flagella are inserted ventrally; one flagellum is transverse and housed in a cingulum and the other is longitudinal and housed in a sulcus. A dinokont dinoflagellate can be a thecate species (with thecal plates) or an athecate species (without thecal plates).
epitheca:
The anterior part of the dinokont-type cell above the cingulum.
estuary:
an arm or inlet of the sea at the lower end of a river.
flagellum:
Whip-like structures arising from the cell and responsible for propelling cells in a watery fluid. All dinoflagellates at some time in their life cycle have two dissimilar flagella: a transverse flagellum (provides propulsion) and a longitudinal flagellum (provides direction). They either emerge through one pore or two separate pores.
heterotrophic:
Capable of utilizing only organic materials as a source of food, as some plants and most animals.
heterotrophy:
Nutritional mode in which absorption of organic matter is required for growth, metabolism and reproduction; e.g. auxotrophy, mixotrophy, myzocytosis, phagotrophy and organotrophy.
hypotheca:
The posterior part of a dinokont-type cell below the cingulum.
hypersaline:
Pertaining, or resembling excessively high amount of salt.
list:
Membranous thecal extensions of armored dinoflagellates (often associated with the cingulum and sulcus); some extension curved or ribbed.
Neurotoxic Shellfish Poisoning (NSP):
A human neurological disease caused by the ingestion of toxic marine shellfish (filter-feeding bivalves). Symptoms are similar to those of ciguatera poisoning and include temperature reversal sensations, as well as headache, chills, and muscle and joint pain. Cases have been reported from the southeast US and eastern Mexico.
nucleus:
A membrane-bound organelle in eucaryotic cells which contains a large percentage of the genetic material in the cell. In dinoflagellates, it is most often referred to as a mesokaryon or a dinokaryon due to its unique feature: chromosomes are permanently condensed.
Paralytic Shell fish Poisoning (PSP):
A human neurological disease caused by the ingestion of toxic marine shellfish (filter-feeding bivalves) as well as other harvested seafood. PSP has been reported from cold and warm seas Shellfish can accumulate and store large quantities of bloom or red tide dinoflagellate toxins without apparent harm to themselves Symptoms include: tingling sensation around lips gradually spreading to face and neck; prickly sensation in fingertips and toes; headache, dizziness, nausea, vomiting, diarrhea. In extreme cases, muscular paralysis occurs resulting in death from respiratory paralysis.
pelagic environment:
Living or growing at or near the surface of the oceans.
pigments:
Any coloring matter in plant or animal cells.
plankton:
Refers to free-living organisms in aquatic environments that have little or no self-motility, and therefore, they float and drift under the action of water movement.
phytoplankton:
Planktonic plant life.
sulcus:
Longitudinal area on the ventral surface of dinokont-type cells that forms a pronounced furrow or depression that houses the longitudinal flagellum. In thecate species, the sulcus is made up of sulcal platelets (designated by 's'). This feature is not present in some desmokont-type cells.
thecal plates:
Plates of armored (thecate) species which are composed of cellulose or polysaccharide micro fibrils. Their particular size, shape and arrangement on the cell are characteristic to a species.
unarmored:
Dinokont-type cells that do not have an identifiable plate series and do not have apical pore complexes.
valves:
In the thick-walled desmokont, two opposing halves of the theca are called valves (right and left). The right valve is the one most indented anteriorly by the periflagellar plates.
ventral:
The front side of an organism (opposite dorsal side): in dinokonts, side of sulcus and juncture of the cingulum-sulcus; in dinokonts, the side of flagellar insertion.

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