Alexandrium fundyense | |
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Scientific classification | |
Phylum: | Dinoflagellata |
Class: | Dinophyceae |
Order: | Gonyaulacales |
Why is Alexandrium spp harmful?
By producing potent neurotoxins, known as saxitoxins (STXs), A. fundyense is responsible for outbreaks of paralytic shellfish poisoning (PSP), which is potentially fatal to humans (Llewellyn, 2006).
Where do alexandrium Catenella come from?
These organisms have been found in the west coast of North America, Japan, Australia, and parts of South Africa. Alexandrium catenella can occur in single cells (similar to A.
Where does Karenia brevis come from?
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.
What toxins does Alexandrium produce?
The dinoflagellate alga Alexandrium fundyense produces a suite of potent neurotoxins (saxitoxin and its derivatives) resulting in Paralytic Shellfish Poisoning (PSP). PSP is known to impair physiological functions in bivalve molluscs and copepods.
What is Alexandrium SPP?
Alexandrium is a genus of dinoflagellates. It contains some of the dinoflagellate species most harmful to humans, because it produces toxic harmful algal blooms (HAB) that cause paralytic shellfish poisoning (PSP) in humans.
How does alexandrium Catenella eat?
Alexandrum tamarense is an autotrophic organism, as is Alexandrium minutum, which obtains energy through photosynthesis.
Is alexandrium Catenella photosynthetic?
Morphology and Structure: A. catenella is a photosynthetic species with numerous yellow-green to orange-brown chloroplasts. The nucleus is large and U-shaped (Whedon and Kofoid, 1936).
What causes paralytic shellfish poisoning?
Causes. Paralytic shellfish poisoning is caused from the ingestion of toxin-contaminated bivalve shellfish and crustaceans. Algal blooms of dinoflagellates, usually during the warmer months of June to October, result in toxin accumulation in filter feeders such as bivalves.
What eats alexandrium Catenella?
Mussels, clams and oysters feed on these dinoflagellates or red algae with which they may be associated and thus become toxic. The carnivorous fish that feed on these organisms will also become toxic.
Does Karenia brevis cause red tide?
What is it? In Florida, red tide is caused by the accumulation of Karenia brevis, a type of single-celled organism called a dinoflagellate. Red tides occur around the world and are not all caused by the same species, nor are they always red. In fact, most dinoflagellates are harmless.
How do you treat Karenia brevis?
brevis toxin may confirm red tide intoxication, in addition to the presence of increased dinoflagellate counts in water samples. Treatment focuses on prevention of drowning. Generally, affected manatees are propped up on foam to keep their heads above water for 24 to 48 hours and closely observed.
What causes Karenia brevis in Florida?
Red tides are caused by an accumulation of a type of microscopic organism called a dinoflagellate, which is found in lakes, rivers, estuaries and the oceans. The particular dinoflagellate that causes Florida’s red tide blooms is Karenia brevis.
Where does saxitoxin come from?
Introduction. Saxitoxins are produced in freshwater and marine environments. In marine environments, they are often referred to as PSPs. Most human saxitoxin toxicoses have been associated with the ingestion of marine shellfish, which accumulate saxitoxins produced by marine dinoflagellates (Cusick and Sayler, 2013).
Which toxin does Gonyaulax release?
Gonyaulax belongs to red dinoflagellates and commonly causes red tides. It secretes a poisonous toxin known as “saxitoxin” which causes paralysis in humans.
What causes Alexandrium blooms?
Alexandrium blooms occur seasonally and are influenced by a multitude of abiotic conditions from temperature, salinity, nutrient availability and even weather patterns. They also are impacted by biological factors including predation, infection from viruses, bacteria, parasites or cell encystment.
What does prorocentrum Lima do?
Prorocentrum lima is a toxic dinoflagellate species known to produce a number of toxic substances: fast-acting toxin (FAT) (Tindall et al., 1989); prorocentrolide (Torigoe et al., 1988); and DSP-toxins (Yasumoto et al., 1987): okadaic acid (OA) (Murakami et al., 1982, Lee et al., 1989, Marr et al., 1992); …
Is alexandrium Catenella autotrophic?
6), the bloom of autotrophic (Alexandrium catenella) species occurred between June and August 2009, after which the pool of the dinoflagellate cysts was dominated by heterotrophic species.
Is Ceratium a phytoplankton?
Ceratium, genus of single-celled aquatic dinoflagellate algae (family Ceratiaceae) common in fresh water and salt water from the Arctic to the tropics. … Members of the genus form an important part of the plankton found in temperate-zone seas, and several are known to cause red tides and water blooms.
Is there a cure for paralytic shellfish poisoning?
There is no antidote for Paralytic Shellfish Poison. The only treatment for severe cases is the use of life support systems such as a mechanical respirator and oxygen until the toxin passes from the victim’s system. Survivors can have a full recovery.
Can you survive paralytic shellfish poisoning?
In patients with mild to moderate poisoning, effects resolve over 2-3 days, but in severe cases, weakness may persist for up to a week. In most fatalities, death occurs rapidly, typically within 12 hours.
How do you treat mussel poisoning?
There is no specific cure available for shellfish poisoning, and antibiotics do not shorten the illness. Drugs used to control diarrhea, vomiting, and stomach cramps should not be used except for bismuth (Pepto-Bismol). These drugs are referred to as antimotility drugs since they decrease stomach and intestine motion.
Where is red tide the worst in Florida?
According to FWC’s red tide map, the worst of the recent blooms are located offshore and onshore of north Pinellas County beaches, near Clearwater, as well as Anna Maria Island and Bradenton Beach in Manatee County.
What caused the red tide in Florida 2021?
A red tide is a naturally occurring phenomenon which is made up of microscopic plankton called Karenia brevis. … These events are known as algal blooms and this specific microorganism turns the usually clear waters red when they are present.
Is there red tide in the Gulf?
Yes, many algae species cause red tides all over the world. Yet, the organism that causes Florida’s red tide, K. brevis, is found almost exclusively in the Gulf of Mexico from Mexico to Florida.
What does Karenia brevis feed on?
brevis consumes. Bacteria transforming nitrogen in the water into more useful forms. Light creating available nutrients from natural, dissolved compounds like tannins in the water.
How large is Karenia brevis?
Karenia brevis is an aquatic marine organism in the phylum Dinoflagellate and super group Alveolates. These flagellated Protists also referred to as algae, are of microscopic proportion usually between 20 and 40 mm in size.
How does Karenia brevis grow?
In addition, they may be entrained by the Loop Current into the Gulf Stream. How does Karenia brevis reproduce? In most cases algae reproduces by asexual fission. This means that one cell grows and then divides into two cells, then four, then eight, then sixteen, and this continues.
Is Karenia brevis a plankton?
Its name is Karenia brevis. It is one of about 10 species of Karenia found in the ocean but it is the dominant form in the Gulf of Mexico. Karenia is referred to as “phytoplankton”, which suggests it is a microscopic plant. … They are a type of phytoplankton called “dinoflagellates” because they have two flagella.
Is Karenia brevis really a low light adapted species?
Studies have described K. brevis as a low-light-adapted species, incapable of sustaining growth under high light, which is at odds with observed surface aggregations sometimes within centimeters of the sea surface and also with short-term experiments showing photosynthetic machinery accommodating high irradiances.
Where is Karenia brevis found?
The species is found worldwide, with toxic blooms of Karenia brevis (formerly known as Gymnodinium breve and Ptychodiscus brevis) being the organism most frequently associated with red tides in the Gulf of Mexico, and occasionally on the Southeast coast of the United States, where it is known as Florida red tide.