''Gonyaulax'' is a genus of

dinoflagellate The dinoflagellates ( Greek δῖνος ''dinos'' "whirling" and Latin ''flagellum'' "whip, scourge") are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered algae. Dinoflagellates are ...

s with the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specim ...

''Gonyaulax spinifera'' (Claparède et Lachmann) Diesing. ''Gonyaulax'' belongs to red dinoflagellates and commonly causes

red tide A harmful algal bloom (HAB) (or excessive algae growth) is an algal bloom that causes negative impacts to other organisms by production of natural algae-produced toxins, mechanical damage to other organisms, or by other means. HABs are sometimes ...

s. It secretes a poisonous toxin known as "saxitoxin" which causes paralysis in humans.

Structure

''Gonyaulax'' is a genus of dinoflagellates that are aquatic organisms with two separate

flagella A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have fro ...

: one extends backward and the other wraps around the cell in a lateral groove helping to keep the organism afloat by rotational motility. The plate formula in the genus ''Gonyaulax'' Diesing was redefined as Po, 3', 2a, 6", 6c, 4-8s, 5'", 1p, 1"".

Classification

All species are marine, except for one freshwater species, ''Gonyaulax apiculata''. It previously included several species, which are now considered to belong to a separate genus, e.g.: *''Gonyaulax tamarensis'' (now: ''

Alexandrium tamarense ''Alexandrium tamarense'' is a species of dinoflagellates known to produce saxitoxin, a neurotoxin which causes the human illness clinically known as paralytic shellfish poisoning (PSP). Multiple species of phytoplankton are known to produce sax ...

'') *''Gonyaulax grindleyi'' (now: ''Protoceratium reticulatum'') *''Gonyaulax polyedra'' (now: ''

Lingulodinium polyedra ''Lingulodinium polyedra'' is a species of motile photosynthetic dinoflagellates. ''L. polyedra'' are often the cause of red tides in southern California, leading to bioluminescent displays on beaches at night. Life cycle As part of its life ...

'')

Adaptations

''Gonyaulax''

s have evolved a type of resting spore (or resting cyst), to enable it to survive harsh weather conditions. Resting cysts can be formed when temperature or salinity changes in the surrounding water. These cysts are round mucous covered bodies that appear reddish in color. ''Gonyaulax catenella'' has been recorded forming vegetative cysts in response to cold water.

Reproduction

''Gonyaulax'' are

protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the e ...

s that may grow in long chains, especially when faced with turbulent water conditions. These chains allow for clustering of organisms for increased mating, and protection of weakly swimming organisms that could otherwise be washed away.

Effect on humans

Although ''Gonyaulax'' is predominantly found in seawater, it can also have a detrimental effect on humans. Filter feeding organisms (e.g. mussels, clams, etc.) can accumulate these dinoflagellates in their bodies. When humans eat these shellfish after dinoflagellate accumulation during Red Tide season, usually during the warmer months of the year, it can poison the person who eats it.

Red tide

Red tide A harmful algal bloom (HAB) (or excessive algae growth) is an algal bloom that causes negative impacts to other organisms by production of natural algae-produced toxins, mechanical damage to other organisms, or by other means. HABs are sometimes ...

is a discoloration of the sea water by pigmented cells like ''Gonyaulax spp.,'' some of which may produce toxins. ''Gonyaulax spinifera'' has been connected to the production of

yessotoxin Yessotoxins are a group of lipophilic, sulfur bearing polyether toxins that are related to ciguatoxins. They are produced by a variety of dinoflagellates, most notably ''Lingulodinium polyedrum'' and '' Gonyaulax spinifera''. When the environm ...

s (YTXs), a group of structurally related

polyether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be ...

toxins, which can accumulate in shellfish and produce symptoms similar to those produced by

paralytic shellfish poisoning Paralytic shellfish poisoning (PSP) is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks (such as mussels, clams, oysters and scallops). These shellfi ...

(PSP) toxins.