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Name: Mrs. Corwin's 5th grade class
Location: N/A
Country: N/A
Date: N/A 


Question:
My 5th grade class would like to know why is it that red tide only affects humans and not lobsters, fish, etc. Why is the micro-organism so toxic to humans?
Waiting to learn....



Replies:
Without going into too much detail, the microorganisms responsible for causing red tide can live within the shellfish without killing them because the chemicals they produce which imbue everything with the characteristic red color aren't toxic to the shellfish. It's just our bad luck that those very same chemicals happen to interact with our body chemistries in the ways that can't occur in shellfish.

--Wordsworth


As it turns out, red tides do affect other vertebrates (animals with backbones), in fact, they are responsible for huge, stinky die-offs of fish that wash up on shore during a "red tide". The microorganism responsible for the occurrence of a red tide is the "dinoflagellate", there are different types of dinoflagellates, and as I understand it, they produce different types of toxins, but usually the toxin responsible for the die-offs is what is called a "neurotoxin", which affects the heart , slowing it down. This reduces blood circulation, and the reduced blood circulation to the gills results in oxygen starvation, and the fish dies. As far as I know, however, this toxin only affects vertebrates, and not invertebrates (animals without backbones) like the clam and lobster.

Tom F Ihde



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