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includinghistamine,asubstancethatourcells
use to signal each other in response to
damage;antihistaminedrugsgivesomerelief.
ShellfishandCiguateraPoisoningsFishand
shellfish share the waters with many
thousands of animal and plant species, some
of which engage in nasty chemical warfare
with each other. At least 60 species of onecelled algae called dinoflagellates produce
defensive toxins that also poison the human
digestive and nervous systems. Several of
thesetoxinscankill.
Wedon’tconsumedinoflagellatesdirectly,
butwedoeatanimalsthateatthem.Bivalve
filterfeeders—mussels,clams,scallops,
oysters—concentratealgaltoxinsintheir
gillsand/ordigestiveorgans,andthen
transmitthepoisonstoothershellfish—
usuallycrabsandwhelks—ortohumans.
Accordingly,mostdinoflagellatepoisonings
arecalled“shellfishpoisonings.”Many
countriesnowroutinelymonitorwatersfor
thealgaeandshellfishforthetoxins,sothe
greatestriskisfromshellfishgathered
privately.
Thereareseveraldistincttypesofshellfish
poisoning,eachcausedbyadifferenttoxin
andeachwithsomewhatdifferentsymptoms
(seeboxbelow),thoughallbutoneare
markedbytingling,numbness,andweakness