On Sun, 26 Nov 2006 22:22:18 -0800, Bert Bartleson
<[log in to unmask]> wrote:

>Hi Paul, there are many other species you can add to your list of mollusks
>that can make you very sick.  For example, in the Pacific NW we had some
>people become sick after eating Fusitriton oregonensis (Redfield, 1848).
>The salivary glands contain a toxin.  These snails are quite large
(commonly
>4 inches long) and scuba divers often collect them.  They are in the
family
>Ranellidae.
>
>In Asia (China and Taiwan), many different species of snails can become
>toxic when certain bacteria colonize them and produce TTX (tetrodotoxin).
>This toxin is quick acting and deadly (the same toxin sometime kills sushi
>eaters in Japan when fugu is not properly prepared). Some of the snails
>linked to illness include: Charonia sauliae, Tutufa lissostoma, Babylonia
>japonica, Rapana rapiformis, R. venosa, Natica lineate, N. vitellus,
>Polinices didyma, and several species of Nassariidae (Nassarius clathrata,
>Zeuxis scalaris and Z. siquijorensis).
>
>These are in addition to the PSP and mercury poisonings already discussed.
>
>Bert Bartleson Olympia, WA. USA
>
>-----Original Message-----
>From: Conchologists List [mailto:[log in to unmask]] On Behalf Of
Paul
>Monfils
>Sent: Saturday, November 25, 2006 10:04 AM
>To: [log in to unmask]
>Subject: Re: Giant clam sushi
>
>Some mollusks are delicious as table fare, others so-so, and some
apparently
>not very palatable.  However, all that I know of are "edible", which is to
>say, eating them wouldn't harm you, and could keep you alive if nothing
else
>was available.  My question is - are there any mollusks known to be
>inedible, that is, toxic if eaten?  (Like berries - some delicious, some
>so-so, some poisonous).  Of course, humans have probably tried eating all
>known berries, and certainly have not tried eating all known molluscs, but
>just thought I would ask if any toxic species are known.
>
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I am currently researching seafood toxins for a section of my website on
Seashore Foraging at www.coconutstudio.com so I´m grateful that this
subject has come up, with some very useful new information.

So far as I can tell, almost all seafood toxins derive from secondary
bacterial or algal 'infection', of which there are several different
types, some of which are indeed very nasty. 'Red tides' or algal blooms
are a particular cause, and no filter-feeding sessile shellfish should be
eaten during those times (or to be careful, in any summer month without
an 'R', when warmer waters can boost algal growth).

The mercury poisoning is a similar human-induced problem. Minamata was the
first publicised occurrence, but now mercury and other heavy metals are
concentrating in almost any pelagic top predator fish, tuna in particular.
Since 90% of the world´s largest fish have already been caught and eaten,
the problem is steadily moving down the food chain. Even parrotfish, that
sell as exotic tropical delicacies in western supermarkets, but considered
junk fish by the locals, can be toxic because they browse on corals, which
themselves concentrate heavy metals from excess rainwater run-off due to
deforestation, mining, etc.

Red tides are increasing worldwide, including in the USA, and are becoming
a very serious problem. Until recently, few red tides were recorded in the
Philippines outside Manila Bay, which collects the effluent of some 10
million people, but this year, they´re being reported all over the place,
and warnings posted.

Even fugu fish, the infamous puffer fish, are not poisonous when farmed,
suggesting that their toxin is also caused by an algal diet in the wild.
Here in the Philippines people eat doto, the spiny puffer fish, and botete
the ones with softer spines, regularly, and I have heard of no ill
effects. You have to 'peel' the doto carefully after blanching it to
remove the skin, then simmer it in some coconut milk, chopped onions,
chilli and ginger - it´s good, and I´m not in the least bit dead yet.

I think Chris Takahashi was remembering the Shoot-to-Kill restaurants by
the Magellan monument in Mactan. Shoot-to-Kill refers to the different
preparation methods (Sugba - grilling, Tinola -soup, Kinilaw - raw in
vinegar) - not to the well-known habits of Filipinos disposing of each
other after they´ve had too much to drink. You buy the fish or shellfish
at a stall, then a seashore restaurant prepares it for you.

You can see more on shoreline foraging at:
http://www.coconutstudio.com/Shoreline%20Foraging.htm
- a day´s catch on the reef

http://www.coconutstudio.com/cuisinebyseashore2.htm
- preparing Melo, Angaria, and Nerita

http://www.coconutstudio.com/kinilaw_art.htm
- raw seafood in general

http://www.coconutstudio.com/Philippinecaviare.htm
- seaweeds to eat and lukot (to be corrected - I´ve found out now that
this marine spaghetti is the eggs of a seaslug, not the kind of excreta I
was thinking of - but delicious anyway)

We haven´t been affected by any kind of seafood poisoning, and I´ve never
heard of anyone getting sick locally, except for one guy who swallowed a
live ghost crab for a dare (and he should have known better - he knows
what the locals use the beach for).

regards

Richard

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