Last week I blogged about pufferfish and the lethal tetradotoxin that they contain, and we discussed their use as possible murder weapons. Today I want to talk about a couple of other interesting sea toxins that could be incorporated into your murder scenes.

Saxitoxin: This toxin is produced from marine plankton contaminated with toxic algae, such as blue-green algae and Red Tide (as discussed in my blog on harmful algae blooms). Saxitoxin is abbreviated as STX and is alternately referred to as Paralytic Shellfish Toxin (PST) and Paralytic Shellfish Poisoning (PSP). This toxin accumulates in shellfish (clams, mussels and scallops) when these shellfish consume tainted plankton.

This chemical is highly toxic. It can kill in very small oral doses (about 0.5mg for a normal sized person). If the toxin is injected or applied to an open wound, only one-tenth of that dose would be needed to kill (as little as 0.05mg).

Poisoning by inhalation, however, requires larger doses (about ten times the oral dose), but that’s still a mere 5mg and a smaller lethal amount than many aerosolized poisons.

The lethal potential of saxitoxin makes it a major concern as a terrorist weapon, particularly since this toxin can be synthesized in a lab rather than harvested from infected shellfish for potential use as a chemical weapon.

Saxitoxin is about 1000 times more toxic than sarin nerve gas. In fact, Saxitonin already has a military history. The United States previously designated it as a chemical weapon and provided saxitoxin-impregnated needles to elite US soldiers for use as a suicide tool if captured and tortured for top-secret information.

It has been said that U2 pilot Gary Francis Powers had a hollow silver dollar on his person when he was shot down in 1960 over Soviet airspace and that the coin contained an STX-impregnated needle to use at his discretion for suicide.

The symptoms of saxitoxin involve paralyzing the nervous system, but the onset involves a “flaccid paralysis”—leaving the victim calm, relaxed and conscious before paralysis sets in. Death ultimately results from respiratory failure when the muscles of the diaphragm cease to function.

Ciguatera: This food-borne toxin causes illness in humans from contaminated reef fish. The source of the contamination is from marine microalgae called dinoflagellates found in tropical and subtropical waters and which transfer to fish as they feed. Since larger fish feed on smaller ones (and the smallest consume the microalgae), the toxin moves up the food chain. Predator species near the top of the chain are more likely to cause illness because of the greater concentration of toxins from multiple feeds on contaminated fish.

The toxin is odorless and tasteless. It’s very heat-resistant, so conventional cooking does not detoxify the poison. The good news is that this toxin usually produces illness rather than death.

The symptoms of Ciguatera poisoning are GI distress (nausea and vomiting) and a variety of neurological symptoms (such as tingling fingers and toes, vertigo, and hallucinations). An interesting neurological effect is that the victim may find that cold things feel hot and hot things feel cold. The poisoned person may even be misdiagnosed with multiple sclerosis (MS).

Even though the toxin may not be lethal, there is no cure and symptoms can range from short-term to long-term. The victim may recover in days to weeks but the effects of Ciguatera poisoning may last for years (even 20 years or longer) and can cause long-term disabilities (coordination and speech problems). Most recover slowly over time, but it should be noted that during the recovery process exercise could trigger onset of further symptoms. A particularly nasty villain in your novel might get what he deserves with such a toxin.

Fortunately, there are lab tests to detect the presence of this toxin and Liquid Chromatography-Mass Spectrometry is most often used.

Previous to this science, “folk detection” was used to identify contaminated fish. Ancient cultures determined that flies would not land on such fish. Alternately, silver coins were put under the scales of a fish. If the coin turned black, the fish was not eaten. One can assume that the owner was happy to have a tarnished coin to spend on something other than a funeral.

As with my previous postings on murder weapons, I hope this information has stimulated the creative juices to plan and plot unusual murder scenes that will delight your readers.

Thoughts? Comments? I’d love to hear them!