418 Dive Log Australasia JUNE 2026.pdf

Cone-an the Barbarian: CONE SNAILS by GORDON CROFT S nails are classified as gastropod (“stomach foot”) molluscs, and can be found on land and in both fresh and salt water habitats. it is estimated that there are in excess of 800 living species. All of them are predatory, and can generally be divided into three groups depending upon what they feed upon. One group, the vermivores , specialize in eating worms, another group, the molluscivores , predate on other

We are all familiar with snails in our garden, and those commonly found in rock pools down on our local beaches, but perhaps the thought of a snail that has developed a complex venom armoury, coupled with a harpoon to deliver it, and which can, in extreme cases, prove fatal to humans, is perhaps slightly beyond our comprehension. But such a group does exist – welcome to the bizarre world of the Cone Snails. As their name suggests, Cone Snails have a distinctive ice-cream cone shape, with a broad end tapering down to a blunt “point”. The shells can be beautifully patterned, and are popular with shell collectors, indeed Rembrandt completed his only still life etching entitled “De schelp” or “The shell” in 1650 depicting a Marbled Cone, Conus marmoreus, Cone snails are sea dwellers that live predominantly in tropical and temperate seas and

snails, including other cones, and the third group are piscivorous and specialize in eating fish. Most molluscs feed using a structure called a radula, which is a ribbon-like organ covered with microscopic teeth. This acts in the same way as a file, rasping away algae, fungi or plant material – if you carefully examine algae covered rocks on a beach you may observe small zig-zag patterns caused by the radular teeth of limpets, scraping away the algae for food. Cone Snails have evolved these teeth into extremely effective venom-delivering harpoons – one is used at any one time, but they store spare teeth ready for use at a later date. The harpoons act in the exact same way as a hypodermic needle, injecting venom previously stored in the

Geographical Cone from Lissenung, New Ireland PNG

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Dive Log Australasia #418 JUNE ’26

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