Life Cycles Moro Toxins Flashcards
What environmental conditions favor cyanobacterial blooms?
High temperatures, intense sunlight, high nutrient concentrations, stagnant water, and in brackish and seawater
What are the three main groups of cyanobacterial toxins?
- Cyclic peptides (e.g., microcystins, nodularins)
- alkaloids (e.g., cylindrospermopsins, aplysiatoxins)
- and neurotoxins (e.g., anatoxin-a, saxitoxins)
Which cyanobacterial toxin is known for causing liver issues and has been linked to liver cancer?
Microcystins, which are cyclic peptides and hepatotoxins
How do neurotoxins from cyanobacteria affect the body?
They block neuromuscular activity by either acting as antagonists of acetylcholine or by blocking sodium channels, causing symptoms like vertigo, shortness of breath, and convulsions
What toxin is produced by Pseudonitzschia spp., a harmful diatom?
Domoic acid (DA), which causes Amnesic Shellfish Poisoning (ASP)
What are the symptoms of Amnesic Shellfish Poisoning (ASP)?
Memory loss, convulsions, abdominal cramps, diarrhea, nausea, and in severe cases, coma and death
Which dinoflagellate toxin causes Paralytic Shellfish Poisoning (PSP)
Saxitoxin, produced by Alexandrium, Gymnodinium, and Pyrodinium species
What is the main effect of brevetoxins produced by Kerenia brevis?
Brevetoxins cause Neurotoxic Shellfish Poisoning (NSP) by opening voltage sodium ion channels, leading to uncontrolled sodium influx and symptoms like nausea and loss of motor control
Which toxin is responsible for Diarrhetic Shellfish Poisoning (DSP)?
Okadaic acid (OA) and dinophysistoxins (DTXs), produced by Dinophysis and Prorocentrum species
What are the two main toxins produced by Ostreopsis ovata?
- Palytoxins (PTX)
- Ovatoxin-a
What conditions favor the growth of Ostreopsis ovata?
High temperatures, high lighting, presence of seaweeds, low hydrodynamics, presence of breakwaters, and nutrient-rich environments.
How can humans be affected by toxins from Ostreopsis ovata?
Through ingestion via the food chain, inhalation of aerosols, and direct contact with contaminated seawater, causing symptoms like fever, cough, shortness of breath, headache, and vomiting.
What is the impact of Ostreopsis ovata toxins on marine life?
It can cause muscle tissue damage in seabream, edema in cuttlefish, spine loss in sea urchins, die-off in mussels, death in barnacles, and arm loss in sea stars.
What is the common effect of neurotoxins produced by marine organisms?
They interfere with nerve impulse transmission, often by interacting with ion channels involved in neurotransmission.
Why are some marine toxins used as biochemical reagents and drugs?
Because of their ability to modulate the activity of numerous cellular proteins, such as ion channels and receptor proteins.
