HAB Glossary of Selected Terms
What is an apical pore? Look here to find out about this and other words associated with microscopic algae.
Aerosolized toxins
Toxins released through spray or mist
Amino acid
One of the 20 building blocks of protein
Amnesic shellfish poisoning (ASP)
Illness caused by eating shellfish that have fed on diatoms that produce the toxin domoic acid; symptoms include a decreased reaction to pain and short-term memory loss
Anoxia
Lacking oxygen
Anterior-posterior attachment
When cells are connected to each other at the top and bottom to form chains
Apex (apices)
Anterior-most part of the cell; usually associated with apical pore complex (APC) or apical groove
Apical groove
An anterior, narrow groove that can have various alignments on the epitheca of unarmored species
Apical pore
A hole at the top of most armored dinoflagellate cells
Apical pore complex (APC)
Consists of apical pore, the plate (or membrane) that covers the pore (if present), and an accessory plate (if present)
Aquaculture
The growth of freshwater and marine organisms for food on a commercial scale in a confined area or volume of water
Armored
Refers to dinoflagellates that are covered with adjoining cellulose (or other polysaccharide) plates (thecate); plate pattern is characteristic for armored genera
Autotroph
An organism that makes its own organic food by photosynthesis or chemosynthesis
Benthic
Pertaining to all undersea bottom terrain, regardless of water depth
Bioluminescence
Biologically produced cold light
Biotoxin
A biologically produced toxin
Biotransformation
The chemical alteration of a substance within the body, as when organisms metabolically change toxins and the toxins’ activity
Bivalve mollusk (mollusc)
An organism with a two-part shell (e.g., oyster or clam) belonging to the phylum Mollusca
Bloom
A higher-than-normal population of phytoplankton or microalgae within the water column
Brackish
Water of less than normal oceanic salinity, usually ranging from 0.5 to 17 parts per thousand (ppt) up to 32 ppt
Brevetoxin
A neurotoxin reported (and verified) from Karenia brevis and Chattonella species
Chain / Chain-forming
Description of cells (both diatoms and dinoflagellates) that are attached to form a line or "string" of cells; the cells can be connected by anterior-posterior attachment or cell overlap
Chloromonad
Green flagellates in the class Chlorophyta
Chloroplast
The cellular organelle in which photosynthesis takes place
Ciguatera fish poisoning (CFP)
A human disease caused by eating certain tropical fish that contain the toxin ciguatoxin and its derivatives; the toxins are from dinoflagellates; over 400 tropical fish species are implicated; affects the gastrointestinal and neurological systems; the characteristic symptom is hot-cold reversal
Cingulum / Girdle / Transverse groove
In dinoflagellates, this structure is a furrow encircling the cell, once or several times; if several times, the cingulum is twisted around the cell (cell torsion)
Cleptochloroplast
Stolen chloroplast; can be digested or remain functional and photosynthesize for a limited period
Cosmopolitan
Occurs everywhere; widely distributed
Cyanobacteria / Blue-green algae
Simple plant-like bacteria that are generally blue-green in color; individual cells, filaments, or colonies often float at the sea surface
Cytotoxicity
Toxic to a cell; can disrupt cell metabolism or the cell membrane
Cyst
A dormant or quiescent organism; typically has a protective covering
Desmokont
A dinoflagellate cell type in which two dissimilar flagella emerge from the anterior part of the cell (e.g., Prorocentrum)
Diatom
Planktonic microalgal form with siliceous shell (shaped like a pillbox); occurs as a single cell or in a chain of connected shells; capable of photosynthesis
Diarrheic shellfish poisoning (DSP)
Illness caused by eating shellfish that have fed on Dinophysis or Prorocentrum dinoflagellates, which produce a suite of toxins including okadaic acid, dinophysis toxins, and pectenotoxins; causes gastrointestinal disorders; not life threatening
Differential interference contrast (DIC)
A techique used in light microscopy that separates and recombines light to enhance contrast
Dinocyst
Short- or long-term resting stage in the life history of some dinoflagellates; can be represented in the fossil record
Dinoflagellate
Unicellular microorganism with two flagella (at some time during the life cycle); cells can be armored or unarmored; approximately half photosynthesize; class Dinophyceae, phylum Pyrrhophyta
Dinokont
A dinoflagellate cell type in which two flagella are inserted ventrally; one flagellum is transverse, is housed in a cingulum, and provides propulsion and the other flagellum is longitudinal, is housed in a sulcus, and provides direction
Dinophysis toxin
A toxin produced by Dinophysis species
Dinophysoid
Refers to armored dinoflagellates (e.g., Dinophysis and Amphisolenia) that have a cingulum, a short sulcus, and 18 to 19 plates; the cell looks like it has two opposing halves
Domoic acid
Toxin produced by some Pseudo-nitzschia species
Dorsal
Refers to the "back" of a dinokont cell, as opposed to the ventral (front) where the sulcus is located
ELISA
Enzyme-linked immunosorbent assay; a chemical method for the detection of toxins such as brevetoxin
Epibenthic
Living on the surface of the bottom
Epitheca / Epicone / Episome
Anterior part of dinokont-type cell above the cingulum
Estuary
A semi-enclosed body of water that is connected to the open ocean, within which freshwater (from the land) mixes with seawater
Eutrophic
A body of water that is rich in organic nutrients
f/10
A type of media, in a diluted form
Filter feeder
An organism that obtains food by filtering particles from the water column; also called a suspension feeder
Flagella (plural) / Flagellum (singular)
A long, whip-like projection used for locomotion
Food vacuole
Internal organelle of a cell that accumulates waste products or food being processed
Frustule
The cell or case surrounding a diatom; composed of silica and pectin
Gonyaulacoid
Refers to predominantly photosynthetic armored dinoflagellates that are different from peridinioids in symmetry of plate patterns
Gymnodimine
A toxin isolated from Karenia mikimotoi and associated with fish kills
Gymnodinioid
A type of unarmored dinoflagellate (e.g., Gymnodinium cells)
Hemolysin
A substance that lyses, or breaks up, blood cells
Heterotroph
An organism that ingests and absorbs organic materials for carbon source and energy (e.g., animals)
Hypnozygote
Diploid zygotic stage in the sexual life cycle of dinoflagellates
Hypotheca / Hypocone / Hyposome
The smaller portion of a diatom's frustule or the posterior part of a dinokont-type cell below the cingulum
Indigenous
Native; living or occurring naturally in a specific environment
Intercalary (band)
Area of growth on the theca in armored dinoflagellates or a specific plate in diatoms and other groups; may form bands of silica or scales, which extend inward to form septa
K/10
A type of dilute medium
Kofoidian terminology
Follows Charles Kofoid’s nomenclature for plate tabulations and series for dinoflagellates; modified by Enrique Balech
Lugol's solution
A potassium iodide solution used for fixing and preserving cells
Maitotoxin
A toxin produced by Gambierdiscus toxicus
Medium
An enriched food form (solid or liquid) made of seawater, vitamins, and nutrients; used to grow phytoplankton and microalgae; other types of media are used in other areas of biology
Microalgae
Microscopic aquatic plants; can live in the water column or attached to sediments, plants, and even animals
Mixotroph
A photo-autotroph that is capable of utilizing organic compounds or particles; also a facultative autotroph
Molluskan (molluscan) shellfish
Type of shellfish that belongs to the phylum Mollusca (e.g., oysters, clams, and gastropods)
Neurotoxic shellfish poisoning (NSP)
Illness caused by eating shellfish that have accumulated brevetoxin and its derivatives; not fatal; the main symptoms include tingling and/or numbness of the lips, tongue, throat, hands, and feet
Niskin bottle
A bottle with two openings, one on each end; both ends can be closed simultaneously to capture a discrete sample of water from a particular depth
Nucleus
A cellular organelle found in eukaryotic cells that is surrounded by a membrane and contains the chromosomes
Nutrient
Any substance required by an organism for normal growth and maintenance; a mineral nutrient refers to inorganic substances (such as nitrate, phosphate, or silica)
Oceanic
Pelagic waters in the open ocean, beyond the waters of the continental shelf
Okadaic acid
A toxin produced by Prorocentrum, Dinophysis and Phalocroma species
Oligotrophic
Waters that are low in nutrients and biomass
Paralytic shellfish poisoning (PSP)
Illness caused by eating toxic shellfish; neurological symptoms include tingling, numbness and burning of lips and fingertips; in severe cases, respiratory paralysis can cause death within 24 hours; the toxins are saxitoxin and its derivatives
Peduncle
Cytoplasmic appendage located near the flagellar pores in some dinoflagellate species; an extensible organelle associated with phagotrophy
Peridinioid
A type of armored dinoflagellate; plates are arranged in classic four to six horizontal plate series, with one ventral plate extending from the cingulum to the apex; some are nonphotosynthetic
Periflagellar
Area around the flagella insertion in desmokont dinoflagellates
Pfiesteria species
Belongs to the genus Pfiesteria
Pfiesteria-like
Morphologically similar to Pfiesteria; can be toxic or nontoxic
Phagotrophy
An organism that ingests solid food particles
Phytoplankton
Plant organisms that drift in the water column; they are unable to swim or are too small to resist currents
Planktonic
Refers to those organisms that live suspended in the water column; organisms are incapable of moving against currents
Planozygote
A motile zygote (2N) cell produced by the fusion of gametes (1N); can be morphologically similar to the vegetative (1N) cell
Plate
Part of the theca in armored dinoflagellates; composed of cellulose or some other polysaccharide microfibrils; formed in thecal vesicles that may contain other membrane or osmophilic-staining structures
Plate formula
Tabulation of plates in horizontal series; used to describe armored dinoflagellates
Prorocentrolide
A toxin produced by Prorcentrum species
Protista
Kingdom of single-celled organisms; includes diatoms and dinoflagellates
Red tide
A harmful algal bloom (HAB); refers to a bloom of toxic or harmful marine microorganisms that may color the water; toxins may also be released
Reef fish
Finfish living on or near a coral (or artificial) reef
Saxitoxin
Highly toxic neurotoxin that causes PSP
Septa (plural) / Septum (singular)
An inward growth of intercalary bands on the valves of certain diatoms
Shellfish
Can refer to marine organism belonging to the phylum Mollusca and the class Crustacea (e.g., crabs and lobsters); generally, shellfish refers to mollusks
Sternum
An elongate part of the diatom valve where areolae are sparse or missing
Stria (singular) / Striae (plural)
A linear row of areolae, alveoli, puncta or other ornamentation in some diatoms
Sulcal torsion
Occurs in unarmored dinoflagellates when the girdle and sulcus twist around the cell
Sulcus
Longitudinal furrow on the ventral surface of the cell that houses the longitudinal flagellum
Theca
Multiple membrane complex with vesicles; some species have scales; all dinoflagellates are thecate, some are armored with plates in Kofoidian series
Tychoplanktonic
Refers to benthic organisms accidentally swept up into the water column
Unarmored (naked)
Refers to dinokont cells that do not have plates in a Kofoidian series
Valves
In thick-walled desmokonts, two opposing halves of the theca
Ventral pore
A hole in the ventral surface of (mainly) armored dinoflagellates; typically associated with a specific plate
Vesicle
Polygonal structures that are membrane bound and usually compressed against one another in the cell covering or theca
