Cone Snails Attract Worms Only To Become a Meal

Researchers found that cone snail venom has two molecules that simulate bristle worm pheromones and trigger mate behaviors, all into tricking the worms into becoming a meal.

This finding, reported in Science Advances and entitled "Small-molecule mimicry hunting strategy in the imperial cone snail, Conus imperialism," specifies that typically it takes a full moon's ghostly light to charm certain worms hidden on the seafloor to mate.

There, out in the open, sex-inducing chemicals are kicking off a swirling dance, culminating in what science describes as a moonlit shower of sperm and eggs. However, just a smell of cone snail venom might get the worms in the mood, as well.

According to University of Copenhagen medicinal chemist Joshua Torres, the finding increases the possibility that the cone snails are "weaponizing" the worms' own pheromone as a kind of attraction. Such a behavior, Torres added, is very peculiar.

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Self-Made Harpoons

A ScienceNews report indicates that, cone snails are packing their potent venom into self-made harpoons, which they throw into mollusks, fish or worms.

Each of the over 700 cone snail species' venom is said to be a treasure trove of chemicals hijacking particular physiological pathway in their prey.

For instance, a single cone snail species is producing its own fish insulin that saps the blood sugar of its prey, making it an exhausted target.

The specificity of action of venom has caught the attention of drug researchers. Prialt, a morphine-like painkiller, for instance, stemmed from cone snails.

Torres, together with his colleagues, were keen to scour the cone snail or Conus imperialis' venom. C. imperialis is a diverse species that hunt worms and may be used for potential medicines.

Chemical analysis showed two compounds that piqued the interest of the researchers. These compounds include Conozolium A and genuanine.

Surprising Result

To the chemist's surprise, these tiny molecules did not appear to target neuromuscular pathways and damage their function like a lot of venom elements. However, the molecules were notably similar to mating pheromones of some bristle worms.

Chemically, the emulations of snails are actually more stable compared to the natural pheromones of worms, which degrade comparatively fast after release, according to Torres. Such a match, the study specified, seemed quite perfect to be coincidental.

In addition, while venom is typically doing its dirty work through injection, there are some instances of cone snails that release chemicals into the water column.

To test this appealing hypothesis, the scientists had the Platynereis dumerilii worms exposed in petri dishes to the pheromone mimics.

When hit with the chemicals from snail, out of 16 mails in the experiment, 13 of them released sperm. Meanwhile, out of 11 females, seven started to swirl around in tight circles. This was a precursor to mating.

Hunting Behavior

While C. imperialis is not known for eating this particular worm, the researchers discovered that the DNA of close relatives in some snails' guts, proposing that the compounds could be used as protection from more common prey like fireworms.

Zoologist and evolutionary biologist Thomas Duda from the University of Michigan in Ann Arbor said that cone snails are full of surprises and this study, which he is not involved, raises an exciting probability. The next step, Duda added, should be to figure out how such a finding is actually working in nature.

Hunting behavior of the C. imperialis, according to Torres, is more often than not, known from laboratory investigations, where the worms are sitting ducks for snails.

In the wild though, these tiny creatures are spending time hiding underneath sediments and cracks. Observations in more natural environments could vary if the specialized venom of C. imperialis attracts worms with the promise of mate, only to turn into a meal.

Related information in shown on National Geographic's YouTube video Below: