On Okinawa the cone Shells are generally occupants of warm shallow waters, the poison of some cones can be lethal to humans. Their eggs are deposited in purse-shaped capsules. There are between 400 to 500 species of known cone shells. Although they vary greatly in size and color, all are similar in their distinctive cone shape.
They have either a very thin or thick colorful cone shaped shell of varying stripes or speckled appearance. These shells can be very attractive and because of this, may be picked up by the unwary, especially children.
Besides their usually appallingly regular form cone shells also are collected because of the beautiful colour patterns from the beaches of Okinawa. Divers that try to get hold of one of the demanded shells should keep in mind that the beautiful and sometimes very expensive shells (Conus gloriamaris - the glory of the sea achieves a price of several hundered dollars and pictured below) may still be occupied and that cone shells do not hesitate to defend themselves with venomous stings. It can be taken for probable that the most dangerous cone shell to humans is Conus geographus. Of 16 casualties up to 1979 12 were because of this snail, 2 because of Conus textile and 2 could not be associated to a certain species. Many more cone shell encounters were painful but non-fatal.
Cones are able to immobilize their prey with a modified, harpoon-like tooth. The tooth can be extended at least the length of the cone’s shell. The cone animal locates its prey using its sense of smell. Once the prey is detected, the long tooth is plunged into its victim. Once paralyzed, the prey is swallowed whole. Digestion proceeds over a period of hours and concludes with the expulsion of undigested parts like shell or bone. Most cones eat other mollusks, but a few evolved species hunt fish. At least 10 human deaths in the South Pacific region have been attributed to Cone stings.
Cone shells are commonly found around Okinawa.These little animals can be very poisonous. Nearly all of the 500-600 species have a distinctively similar shape. Characteristic features are: a flat top, conical shell; and, a long slit-like aperture lip extending from a very short siphonal opening to nearly the top. Some species have moderate spires, although generally similar. The shell may be smooth or spirally ornamented, and the patterns and colors are extraordinarily varied.
All are carnivorous and feed on other mollusks, worms and small fish, which they stun by projecting a venomous harpoon connected to a muscular poison gland. The cone can extend its proboscis lightning fast for a lethal sting and engulf and digest a fish the size of its shell or larger. This mode of feeding is shared by other molluscs in the superfamily Conacea, which includes Turrid and Auger Shell molluscs.
The venom consists of numerous neurotoxic peptides and can result in the death of humans. The venom acts pre and post-synaptically to give rise to neurological symptoms such as weakness, lack of coordination and disturbed vision, hearing and speech. Severe cases may result in death secondary to respiratory muscle paralysis. Less common systemic symptoms include nausea. Local symptoms of pain, swelling and numbness are common.
In some cones, the venom is powerful enough to be lethal to collectors who are not careful in handling the mollusc.
If stung by a cone shell, obtain medical attention immediately (making note of a description of the cone shell if possible). If medical attention is unavailable and the victim becomes unconscious, observe their breathing constantly and apply assisted and artificial respiration when required until assistance can be found. In this way it may be possible to keep the victim alive while the body metabolises the conotoxins. Pressure immobilisation first aid should be applied and left in place until resuscitation facilities are available. This is a medical emergency. Assisted ventilation may be needed. Tetanus prophylaxis should be updated if required. There is at present no antivenin for cone shell stings.
