Cone Shells are soft bodied molluscs, they are protected by a shell secreted by a skin like mantle which covers its body. Also known as Arrow Tongues they belong to the phylum Mollusca and are classed as Gastropods. It has a muscular foot, a distinct head with eyes, tentacles and a mouth, It has a tongue like band of teeth called radula that rasp off or drill into its prey. It has an operculum (horny plate) that closes off its shell opening. Cone shells have come into the fore recently for scientific research as their venom has pharmacological qualities valuable to medical research. The venom differs between species and individual snails. It consists of small peptides toxins, amino acid residues of high density disulfide bonds. Their pharmacological properties change and the paralytic components include alpha, omega and mu conotoxins. These toxins prevent neuronal communication by targeting nicotinic ligand gated channels, sodium channels and calcium channels. They have been gathered by beach goers for centuries to add to collections. The Cone Shell is a gastropod, a marine snail found in most waters around the world. To survive in its envrionment the snail has developed a very potent toxin, it contains neuronal toxins designed to paralyze its prey. Produced in a long tubular duct the venom is injected via a muscular bulb through the tooth that is shot harpoon like into its victims soft tissue, remaining atttached to the Cone shell via a thread. Once the victim is paralysed by the venom the snail retracts the thread and engulfs the meal. The Cone Shell is classified according to its prey, either piscivorous (fish eating), Molluscivorous (mollusc eaters) or Vermivorous (worm eaters). It detects its prey by a siphon which bristles with chemoreceptors alerting it to nearby victims. It is well advised that they are not handled even with gloves and the tip is avoided at all times. There have been reports of victims of Cone Shell darts not realising that they have been stung and once symptoms have become apparent and the cause established it has been to late to save them.
Signs and symptoms
- Stinging sensation
- Burning pain
- Vision, speech and hearing disturbances
- Nausea- Pruritis
- Loss of coordination
- Cardiac arrest
NB: There is no antivenom for cone shell barbs.
1. Scrub the wound
2. Seek immediate medical aid
3. Pressure / Immobilisation (compression bandage)
4. Commence CPR if indicated
Severe cases, seek medical treatment as soon as possible.
Consult your doctor for treatment with suitable medications
Aw, M. (2000). Tropical reef fishes: A getting to know you and indentification guide. OceanNEnvironment Ltd: Australia.
EMedicine online: www.emedicine.com
Diving Medicine onlinet: www.divernnet.com/medical
PLEASE NOTE - DISCLAIMER:
The information provided above is for general purpose use and provided as guidance that is suggestive, not prescriptive, invasive, or medical in nature. You should always consult with or see a medical practitioner for definitive health care information or to receive medical treatment.