| Chatonella | |
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| Genus: | Chatonella Biecheler 1936 |
| Type species | |
| Chatonella subsalsa Biecheler 1936 | |
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Chattonella is a genus of the marine classraphidophytes associated with red tides and can be found in the phylum Heterokontophyta instramenopiles.[1] These unicellularflagellates are found in brackish ecosystems. The genusChattonella is composed of five species:C. subsalsa,C. antiqua,C. marina,C. minima, andC. ovata.[2]
TheChattonella species contain anectoplasm with vacuoles, chloroplasts, and mucocysts and anendoplasm 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 theChattonella genus is very similar or identical in DNA sequencing.[3]C. minima has an identical morphological structure toC. antiqua, so researchers are developing ways to search for the gene responsible for differentiating between the differentChattonella strains.[4] The only currently known difference between the two strains is the number of chromosomes;C. minima contains 90-110 chromosomes whileC. marina contains 29 chromosomes.[1]
Chattonella algal blooms synthesis is compared to "diatom resting hypothesis" with the only major difference being thatChattonella cysts can germinate in the dark as opposed todiatoms which can germinate only in sunlight.[1] Factors such as water temperature, salinity, irradiance, and nutrients each contribute to the growth ofChattonella.[1]
Algal species can be beneficial, neutral, or harmful to environmental ecosystems. Three of these species,C. antiqua,C. marina, andC. ovata, contribute the growing problem ofharmful algal blooms (HAB).[4]Chattonella outbreaks are known to be enhanced byeutrophication.[1]C. verruculosa was originally categorized with these toxic species, but furtherphylogenetic analysis showed it actually belonged to classDictyochophyceae, notRaphidophyceae.[3] These harmful algal species trigger thenecrosis 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 asThunnus 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.
To preventChattonella HABs, the individual species must first be studied. A technique usingmonoclonal antibodies can be used to identify the genus, while theRAPD reaction can be used to distinguish between different species within the genus. Other researchers use PCR-RFLP is also used to identify species ofChattonella.[4] They sequence ITS rDNA and rRNA, andmitochondrial 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 differentChattonella species.[4]