What toxins does alexandrium produce?
The dinoflagellate produces saxitoxin, which is a highly potent neurotoxin. If consumed, this toxin can cause paralytic shellfish poisoning (PSP). By ingesting saxitoxin, humans can suffer from numbness, ataxia, incoherence, and in extreme cases respiratory paralysis and death.
Which phytoplankton causes paralytic shellfish poisoning?
PSP is caused by planktonic dinoflagellates of the genera Alexandrium, Gymnodinium and Peridinium. These microscopic phytoplankton produce paralytic shellfish toxins (PST), a group of highly potent neurotoxic alkaloids among which saxitoxin was the first to be discovered (Schantz et al. 1975).
What disease does alexandrium Tamarense cause?
The toxic dinoflagellate Alexandrium tamarense is responsible for outbreaks of paralytic shellfish poisoning, one of the most widespread HAB syndromes.
What toxin causes paralytic shellfish poisoning?
The two toxins associated with this poisoning, saxitoxin and gonyautoxin, are produced by marine microalgae dinoflagellates that are associated with harmful algal blooms, such as “red tides,” and are then accumulated in bivalve shellfish to give rise to “paralytic” shellfish poisoning.
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.
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).
What causes 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 organism causes neurotoxic shellfish poisoning?
Neurotoxic shellfish poisoning (NSP) is caused by consumption of molluscan shellfish contaminated with brevetoxins primarily produced by the dinoflagellate, Karenia brevis.
Is alexandrium a phytoplankton?
Multiple species of phytoplankton are known to produce saxitoxin, including at least 10 other species from the genus Alexandrium….
| Alexandrium tamarense | |
|---|---|
| Scientific classification | |
| (unranked): | Alveolata |
| Phylum: | Dinoflagellata |
| Class: | Dinophyceae |
What is paralytic shellfish toxin?
Paralytic Shellfish Poison (PSP) is a naturally occurring marine biotoxin that is produced by some species of microscopic algae. Shellfish eat these algae and can retain the toxin. This biotoxin affects the nervous system and paralyzes muscles, thus the term “paralytic” shellfish poison.
Where do alexandrium Fundyense come from?
Alexandrium fundyense grows primarily in low-salinity, marine environments during the spring and summer months. The highest concentrations of Alexandrium cells are generally seen near the surface waters of the Gulf of Maine.
What are the different species of Alexandrium minutum?
Alexandrium minutum species complex includes A. lusitanicum, A. angustitabulatum, A. minutum, A. andersonii, A.tamutum, and A. insuetum. The main difference between this group and the tamarense species complex, is that the A. minutum group species are much smaller and the development of toxicity is much variable, even between different strains.
How does Alexandrium minutum obtain its energy?
Cell Structure and Metabolism. Alexandrum tamarense is an autotrophic organism, as is Alexandrium minutum, which obtains energy through photosynthesis. However, there are heterotrophic species as well. Asexual reproduction through binary fission is most common (steps 1-3 on the life cycle).
Are there any non toxic species of Alexandrium?
Many Alexandrium species are toxic, which can cause both medical and economic harm to humans. The non-toxic species can cause trouble as well. DNA sequencing is one of the most popular ways to identifiy different Alexandrium species. Diagram of life cycle. By Jack Cook, Woods Hole Oceanographic Institution.
What kind of neurotoxin does Alexandrium produce?
Alexandrium produce paralytic shellfish poisoning toxins (PST). PSTs are neurotoxins. They inhibit transmisison of nerve impulses by blocking sodium channels. PSTs are extremely dangerous humans if they consume contaminated fish. Paralytic shellfish poisoning (PSP) can be fatal.