Cone Shells of Hawaii Can Be Deadly
Brown and White Textile Cone Shell
Some Types of Cone Shells are Crepuscular.
Do you like to walk along the sandy beach at dusk – just as the sun slides silently into the ocean? Do you like to sit on the sand in the early evening? Well, if you are on a Hawaiian beach mat dusk and you want to sit down, I suggest you sit on a lawn chair and hold your legs out straight in front of you, ten inches off the ground.
The cone shells reside on Hawaii’s beaches. Cone shells are crepuscular. This fancy word means the cone shells are active just before dawn or at twilight. Some cone shells are nocturnal, not crepuscular.
Cone shells are beautiful, but can be deadly.
There are many fish in the ocean that eat shells, but only the cone shell strikes back and tries to eat fish. More often than not, they succeed. Cone shells have venom glands. They use these to strike out in defense of octopus – their main enemy. Octopuses (octopi is not the right word although I once thought so, too) dine on the animals residing in shells. The cone shell fires venom at an attacking octopus or a carnivorous mollusk.
The main purpose -- or more enjoyable use from the cone shell's perspective -- of the venom, however, is to immobilize its prey. The cone shell’s barbed teeth – which look sort of like arrows – are the next line of ambush for the cone shell. If it is a worm or snail that the cone shell is targeting, he will have conquered the prey easily with these two tactics; the venom and the teeth. But if it is a fish he is trying to catch, he knows the creature could swim away. So he bites into the fish and hangs on with one long tooth until the venom takes effect.
The venom affects the nervous system which first shows symptoms of lack of muscular coordination and eventually respiratory failure. Whether it is a fish, a worm, or a human, the symptoms and result are the same. Depending on the amount of venom excreted, a cone shell occupant can kill a human in five minutes.
Many seashell seekers who walk the beaches of Hawaii do not realize the danger lurking here. And if they do know about cone shells, they need to realize that cone shells can be very difficult to recognize. One reason for this is there are at least 33 kinds in the Hawaiian waters and they vary in design and color. Secondly, the cone shells like to live among rocks and rubble when they find themselves washed up on a beach. They sometimes become layered in brownish matter. This layer is called the periostracum. It is like a layer of moss. It camouflages the cone shell and prevents organisms to take hold and grow on it.
Most cone shells are rather flat on one end, but some are pointed. So you really do need to be careful if you are collecting seashells on a Hawaiian beach. The local people here say that it is a good idea to shake a seashell when you first pick it up if you are not sure whether or not it is a cone shell. In this way, if it is a cone shell, it becomes disoriented and cannot quickly fling its proboscis out toward its new enemy – you.
Cone shell ready to attack
Here's a shell that's pretty harmless
Collecting sea shells can be fun. Be careful, though.
Happy Sea Shell Hunting
The physiology of a cone shell creature is interesting, to say the least.
I am placing a link below so you can go to read the really macabre details of the cone shell creature's methodology and also his unique physiology. The photographs at this site are amazing.
The site is called Marinelife Photography (at MarinelifePhotography.com) and it is the scientific and creative works of Keoki and Yuko Stender.
Here is the link to the excellent marine site with photographs.
ALL RIGHTS RESERVED (c) 2010 Pamela Williams (Pamela Kinnaird W)
Severns, Michael. Hawaiian Seashells . Hawaii, Island Heritage, 2000. Print.
Ms. K. Harris, Interview. May 27, 2010
Photograph 2. Image courtesy of Schristia's Photostream. The Cone Shell (IMG_5458R)
© 2010 Pamela Kinnaird W