i noticed yesterday a small (3/8 inch) cone shell in my tank. Are all types of cone shells dangerous to humans? i try to get a picture soon. thanks in advance.
I would say for now while you know where it's at, try to get it out of your tank into some type of quarentine, even if just a plastic cup with water, for now. That being said, don't use your bare hands... use thick gloves or a fish net with care. That way it won't go into hiding and get you some day when you're not expecting it.
Nope, not all cone snails are dangerous to humans. Very few conotoxins can seriously harm an adult, in fact. However, I wouldn't go around testing to see if the one you have is lethal
Well with 300 species of the genus Conus it would be tough to say without a picture. These species can be divided into three groups based on their prey.
Most species of Conus prey on bristle worms and their venom is not that dangerous. The second group preys on molluscs and are highly toxic while the third group preys on fish and their venom is extremely toxic.
My gut feeling is your seeing a juvenile in a genus and species of another family of snail but that's just my guess without seeing a picture.
I would err on the side of caution though.