Jorge, Your description is a perfect description of Cypraea clandestina! However, you don't find Cypraea clandestina in the Caribbean, unless someone dropped it there! If your specimen is truly a caribbean species, the only thing it could be at that size would be an immature Cypraea spurca acicularis, but I don't think that species has zig-zag lines, even when immature! Strange! Paul M.