''Amoebophrya'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

dinoflagellate The Dinoflagellates (), also called Dinophytes, are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they are also commo ...

s. Members of the ''Amoebophrya'' genus are syndinian

parasites Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...

that infect free-living

dinoflagellates The Dinoflagellates (), also called Dinophytes, are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they are also commo ...

and have varying degrees of host specificity The parasites might act as "biological control agents for red tides and aid in defining species of Amoebophrya." Researchers have found a correlation between host specify and the impact host parasites may have on other organisms. Due to the host specificity found in each strain of Amoebophrya's physical makeup, further studies need to be tested to determine whether the ''Amoebophrya'' can act as a control against harmful algal blooms.

''Amoebophrya'' strains

Different strains of ''Amoebophrya'' have been seen to infect different host species. Though research regarding the specificity of ''Amoebophrya'' is currently underway, the current

hypothesis A hypothesis (: hypotheses) is a proposed explanation for a phenomenon. A scientific hypothesis must be based on observations and make a testable and reproducible prediction about reality, in a process beginning with an educated guess o ...

supported is that they range from non-host-specific to extremely host specific. Over twenty dinoflagellate species have been reported to be infected by some strain of ''Amoebophrya''. It has proven to be difficult to determine whether or not a strain truly is host specific. Host specificity is confirmed not only through the strain's ability to infect various hosts, but their

reproductive The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are al ...

ability afterwards. If the ''Amoebophrya'' strain infects various hosts but is unable to successfully create following generations, then it would be considered host specific. ''Amoebophyra'' is mostly known for its correlation with harmful algal blooms (HABs). Abundance of certain strains have been linked to the decline of some HABs in

marine life Marine life, sea life or ocean life is the collective ecological communities that encompass all aquatic animals, aquatic plant, plants, algae, marine fungi, fungi, marine protists, protists, single-celled marine microorganisms, microorganisms ...

, while others have been found to cause it. The ability of Amoebophrya to significantly reduce the population of HAB-forming dinoflagellates through predation is an essential aspect of its natural history and its contribution to marine ecosystems.

Infection process

During its lifespan, ''Amoebophrya'' alternates between a free-swimming asexual reproductive stage called the dinospore, and a multinuclear growth phase within the host called the trophont stage. A dinospore will attach to the

host (biology) In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasite, parasitic, a mutualism (biology), mutualistic, or a commensalism, commensalist ''guest'' (symbiont). The guest is typically provided with ...

cell’s outer surface, then enter the

cytosol The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells ( intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondri ...

. Most

infections An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

proceed within the nucleus, though some are confined to the

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

. Within ten minutes, the

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

arrives at the host’s

nuclear envelope The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer membranes that in eukaryotic cells surround the nucleus, which encloses the genetic material. The nuclear envelope consists of two lipid bilayer membran ...

and significantly increases in size during the next twenty-four hours. Hosts infected by certain strains of ''Amoebophrya'' such as ''Amoebophrya ceratii'' are unable to

reproduce Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: asexual and sexual. In asexual reprod ...

before the parasite completes its life cycle and kills the host. It will continue to increase in size through nuclear divisions without the need for

cytokinesis Cytokinesis () is the part of the cell division process and part of mitosis during which the cytoplasm of a single eukaryotic cell divides into two daughter cells. Cytoplasmic division begins during or after the late stages of nuclear division ...

, resulting in a

beehive A beehive is an enclosed structure which houses honey bees, subgenus '' Apis.'' Honey bees live in the beehive, raising their young and producing honey as part of their seasonal cycle. Though the word ''beehive'' is used to describe the nest of ...

-like appearance within the host. After killing the host, ''Amoebophrya'' grows to become mobile and wormlike, but soon separates into dinospores. These new dinospores then have a short period of time in which to find new hosts, as their survival time in water is meager. The aquatic environment can greatly affect the success of ''Amoebophrya'', as a nutrient environment can influence its reproductive ability as well as its offspring’s infectivity.

References

{{Taxonbar, from=Q4747469 Dinoflagellate genera Syndiniophyceae Biological pest control agents