Seashells come in various shapes and sizes. And it appears that the seashells from the tropics tend to be larger than those found in the temperate regions.
Far from being just a coincidence, it seems that there is a rational explanation for it. Simply put, this is because the sea snails in the tropics have to devote relatively less energy to shell growth, compared to those in the cold-water regions.
There has been much discussion in recent years about the effect of increasing global temperatures on marine fauna (see also the last issue of this magazine). However, it has often been overlooked that the increasing acidity of the oceans may have an even greater, and more insidious, effect on marine life than just a simple rise in temperature.