Chattonella

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Chatonella
Scientific classification
Domain:
(unranked):
SAR
Superphylum:
Phylum:
Class:
Order:
Family:
Genus:
Chatonella

Biecheler 1936
Type species
Chatonella subsalsa
Biecheler 1936
Species
  •  ?C. harimaOkaichi
  • C. antiqua(Hada 1974) Ono 1980
  • C. marina(Subrahmanyan 1954) Hara & Chihara 1982
  • C. minimaHara & Chihara 1994
  • C. ovataHara & Chihara 1994
  • C. subsalsaBiecheler 1936
Synonyms
  • HornelliaSubrahmanyan 1954 non Walker 1904
  • HemieutreptiaHada 1974

Chattonella is a genus of the marine class raphidophytes associated with red tides and can be found in the phylum Heterokontophyta in stramenopiles. [1] These unicellular flagellates are found in brackish ecosystems. The genus Chattonella is composed of five species: C. subsalsa, C. antiqua, C. marina, C. minima, and C. ovata. [2]

Contents

Structure and synthesis

The Chattonella species contain an ectoplasm with vacuoles, chloroplasts, and mucocysts and an endoplasm with a nucleus and other organelles. [2] Due to their lack of cell wall, these species have the ability to change size and shape. Therefore, fish populations cannot recognize the toxins and cannot defend themselves. Each species of the Chattonella genus is very similar or identical in DNA sequencing. [3] C. minima has an identical morphological structure to C. antiqua, so researchers are developing ways to search for the gene responsible for differentiating between the different Chattonella strains. [4] The only currently known difference between the two strains is the number of chromosomes; C. minima contains 90-110 chromosomes while C. marina contains 29 chromosomes. [1]

Chattonella algal blooms synthesis is compared to "diatom resting hypothesis" with the only major difference being that Chattonella cysts can germinate in the dark as opposed to diatoms which can germinate only in sunlight. [1] Factors such as water temperature, salinity, irradiance, and nutrients each contribute to the growth of Chattonella. [1]      

Environmental impact

Algal species can be beneficial, neutral, or harmful to environmental ecosystems. Three of these species, C. antiqua, C. marina, and C. ovata, contribute the growing problem of harmful algal blooms (HAB). [4] Chattonella outbreaks are known to be enhanced by eutrophication. [1] C. verruculosa was originally categorized with these toxic species, but further phylogenetic analysis showed it actually belonged to class Dictyochophyceae, not Raphidophyceae. [3] These harmful algal species trigger the necrosis of gill cells in fish. [4] More specifically, the toxins produce reactive oxygen species that disrupt oxygen transport and ultimately lead to suffocation. [1] Fish species such as Thunnus maccoyii, Seriola quinqueradiata, and others are declining rapidly in Australia, Japan, India, China, Brazil, Mexico, and USA, greatly affecting fishing industries. [3] As HABs become more common, more research is dedicated to preventing these outbreaks.   

Analysis methods

To prevent Chattonella HABs, the individual species must first be studied. A technique using monoclonal antibodies can be used to identify the genus, while the RAPD reaction can be used to distinguish between different species within the genus. Other researchers use PCR-RFLP is also used to identify species of Chattonella. [4] They sequence ITS rDNA and rRNA, and mitochondrial DNA of the species to try to target the highly variable regions with molecular markers. [2] [4] [3] Inverted optical microscopes and scanning electron microscopes (SEM) are also used to compare cell size and structure of different Chattonella species. [4]    

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An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria. Algal bloom commonly refers to the rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest.

<span class="mw-page-title-main">Dictyochales</span> Order of single-celled organisms

The silicoflagellates are a small group of unicellular photosynthetic protists, or algae, belonging to the supergroup of eukaryotes known as Stramenopiles. They behave as plankton and are present in oceanic waters. They are well-known from harmful algal blooms that cause high mortality of fish. Additionally, they compose a rich fossil record represented by their silica skeletons.

Amnesic shellfish poisoning (ASP) is an illness caused by consumption of shellfish that contain the marine biotoxin called domoic acid. In mammals, including humans, domoic acid acts as a neurotoxin, causing permanent short-term memory loss, brain damage, and death in severe cases.

<i>Karenia brevis</i> Species of dinoflagellate

Karenia brevis is a microscopic, single-celled, photosynthetic organism in the genus Karenia. It is a marine dinoflagellate commonly found in the waters of the Gulf of Mexico. It is the organism responsible for the "Florida red tides" that affect the Gulf coasts of Florida and Texas in the U.S., and nearby coasts of Mexico. K. brevis has been known to travel great lengths around the Florida peninsula and as far north as the Carolinas.

<span class="mw-page-title-main">Raphidophyte</span> Group of aquatic algae

The raphidophytes, formally known as Raphidophycidae or Raphidophyceae, are a small group of eukaryotic algae that includes both marine and freshwater species. All raphidophytes are unicellular, with large cells, but no cell walls. Raphidophytes possess a pair of flagella, organised such that both originate from the same invagination. One flagellum points forwards, and is covered in hair-like mastigonemes, while the other points backwards across the cell surface, lying within a ventral groove. Raphidophytes contain numerous ellipsoid chloroplasts, which contain chlorophylls a, c1 and c2. They also make use of accessory pigments including β-carotene and diadinoxanthin. Unlike other heterokontophytes, raphidophytes do not possess the photoreceptive organelle typical of this group.

<i>Heterosigma akashiwo</i> Species of alga

Heterosigma akashiwo is a species of microscopic algae of the class Raphidophyceae. It is a swimming marine alga that episodically forms toxic surface aggregations known as harmful algal bloom. The species name akashiwo is from the Japanese for "red tide".

<span class="mw-page-title-main">Ochrophyte</span> Phylum of algae

Ochrophytes, also known as heterokontophytes or stramenochromes, are a group of algae. They are the photosynthetic stramenopiles, a group of eukaryotes, organisms with a cell nucleus, characterized by the presence of two unequal flagella, one of which has tripartite hairs called mastigonemes. In particular, they are characterized by photosynthetic organelles or plastids enclosed by four membranes, with membrane-bound compartments called thylakoids organized in piles of three, chlorophyll a and c as their photosynthetic pigments, and additional pigments such as β-carotene and xanthophylls. Ochrophytes are one of the most diverse lineages of eukaryotes, containing ecologically important algae such as brown algae and diatoms. They are classified either as phylum Ochrophyta or Heterokontophyta, or as subphylum Ochrophytina within phylum Gyrista. Their plastids are of red algal origin.

<span class="mw-page-title-main">Harmful algal bloom</span> Population explosion of organisms that can kill marine life

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 defined as only those algal blooms that produce toxins, and sometimes as any algal bloom that can result in severely lower oxygen levels in natural waters, killing organisms in marine or fresh waters. Blooms can last from a few days to many months. After the bloom dies, the microbes that decompose the dead algae use up more of the oxygen, generating a "dead zone" which can cause fish die-offs. When these zones cover a large area for an extended period of time, neither fish nor plants are able to survive. Harmful algal blooms in marine environments are often called "red tides".

<i>Karenia</i> (dinoflagellate) Genus of single-celled organisms

Karenia is a genus that consists of unicellular, photosynthetic, planktonic organisms found in marine environments. The genus currently consists of 12 described species. They are best known for their dense toxic algal blooms and red tides that cause considerable ecological and economical damage; some Karenia species cause severe animal mortality. One species, Karenia brevis, is known to cause respiratory distress and neurotoxic shellfish poisoning (NSP) in humans.

<i>Pseudo-nitzschia</i> Genus of marine planktonic diatoms

Pseudo-nitzschia is a marine planktonic diatom genus that accounts for 4.4% of pennate diatoms found worldwide. Some species are capable of producing the neurotoxin domoic acid (DA), which is responsible for the neurological disorder in humans known as amnesic shellfish poisoning (ASP). Currently, 58 species are known, 28 of which have been shown to produce DA. It was originally hypothesized that only dinoflagellates could produce harmful algal toxins, but a deadly bloom of Pseudo-nitzschia occurred in 1987 in the bays of Prince Edward Island, Canada, and led to an outbreak of ASP. Over 100 people were affected by this outbreak after consuming contaminated mussels; three people died. Since this event, no additional deaths have been attributed to ASP, though the prevalence of toxic diatoms and DA has increased worldwide. This anomaly is likely due to increased awareness of harmful algal blooms (HABs) and their implications for human and ecosystem health.

Pseudochattonella is a genus of marine, heterokont flagellates belonging to the class of Dictyochophyceae. It currently comprises two species: Pseudochattonella verruculosa and Pseudochattonella farcimen

<i>Akashiwo sanguinea</i> Species of single-celled organism

Akashiwo sanguinea is a species of marine dinoflagellates well known for forming blooms that result in red tides. The organism is unarmored (naked). Therefore, it lacks a thick cellulose wall, the theca, common in other genera of dinoflagellates. Reproduction of the phytoplankton species is primarily asexual.

<i>Alexandrium</i> (dinoflagellate) Genus of single-celled organisms

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Alexandrium catenella is a species of dinoflagellates. It is among the group of Alexandrium species that produce toxins that cause paralytic shellfish poisoning, and is a cause of red tide. Alexandrium catenella is observed in cold, coastal waters, generally at temperate latitudes. These organisms have been found in the west coast of North America, Japan, Australia, and parts of South Africa.

<i>Oxyrrhis marina</i> Species of single-celled organism

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<span class="mw-page-title-main">Mixotrophic dinoflagellate</span> Plankton

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Pseudo-nitzschia australis is a pennate diatom found in temperate and sub-tropic marine waters, such as off the coast of California and Argentina. This diatom is a Harmful Micro Algae that produces toxic effects on a variety of organisms through its production of domoic acid, a neurotoxin. Toxic effects have been observed in a variety of predatory organisms such as pelicans, sea lions, and humans. If exposed to a high enough dose, these predators will die as a result, and there is no known antidote. The potential indirect mortality associated with P. australis is of great concern to humans as toxic algae blooms, including blooms of P. australis, continue to increase in frequency and severity over recent years. Blooms of P. australis are believed to result from high concentrations of nitrates and phosphates in stream and river runoff, as well as coastal upwelling, which are also sources of other harmful algae blooms.

Ana María Gayoso was an Argentine marine biologist, a specialist in study of marine phytoplankton, best known for being the first scientist to describe phytoplankton in the Bahía Blanca Estuary, and to initiate the sustained long-term oceanographic dataset in this ecosystem. She made significant contributions to the understanding of harmful algal blooms caused by toxic dinoflagellate species in the Patagonian gulfs, and was the first scientist to describe high abundances of the coccolithophore Emiliania huxleyi in the Argentine Sea, a key component in the primary productivity along the Patagonian Shelf Break front in the SW South Atlantic. She started the most extensive (1978-present) long-term database of phytoplankton and physico-chemical variables in South America, in a fixed monitoring site in the Bahía Blanca Estuary. She died on 28 December 2004 in Puerto Madryn.

References

  1. 1 2 3 4 5 6 Imai, Ichiro; Yamaguchi, Mineo (2012-02-01). "Life cycle, physiology, ecology and red tide occurrences of the fish-killing raphidophyte Chattonella". Harmful Algae. Harmful Algae--The requirement for species-specific information. 14: 46–70. doi:10.1016/j.hal.2011.10.014. ISSN   1568-9883.
  2. 1 2 3 Demura, Mikihide; Noël, Mary-Hélène; Kasai, Fumie; Watanabe, Makoto M.; Kawachi, Masanobu (November 2009). "Taxonomic revision of Chattonella antiqua, C. marina and C. ovata (Raphidophyceae) based on their morphological characteristics and genetic diversity". Phycologia. 48 (6): 518–535. doi:10.2216/08-98.1. ISSN   0031-8884. S2CID   85252183.
  3. 1 2 3 4 Hosoi-Tanabe, Shoko; Otake, Isamu; Sako, Yoshihiko (2006-11-01). "Phylogenetic analysis of noxious red tide flagellates Chattonella antiqua, C. marina, C. ovata, and C. verruculosa (Raphidophyceae) based on the rRNA gene family". Fisheries Science. 72 (6): 1200–1208. doi:10.1111/j.1444-2906.2006.01277.x. ISSN   1444-2906. S2CID   22773011.
  4. 1 2 3 4 5 6 Kamikawa, Ryoma; Masuda, Isao; Oyama, Kenichi; Yoshimatsu, Sadaaki; Sako, Yoshihiko (August 2007). "Genetic variation in mitochondrial genes and intergenic spacer region in harmful algae Chattonella species". Fisheries Science. 73 (4): 871–880. doi:10.1111/j.1444-2906.2007.01408.x. ISSN   0919-9268. S2CID   46240315.