Tiger Cowrie encounter

Photo Copyright 2010 by Barry Fackler

Last week I was lucky enough to come upon a Tiger Cowrie actively making its way across the reef during daylight hours. I often find Tiger Cowries during the day but the animals themselves are all drawn up into the shells. The few times I've seen the actual living animal has been on night dives years ago.

Photo Copyright 2010 by Barry Fackler

When the animal is active, a thin layer of tissue slides up over the shell. This is called the mantle and is greyish in color having many little projections called papillae. In the photo above, The mantle is extended from the underside and a small slice of uncovered shell is visible on top. The mantle is responsible for the glossiness of the cowrie shell as it protects and polishes the surface.

Photo Copyright 2010 by Barry Fackler

Here, the shell is completely enveloped by the mantle as the snail cruises among the coral peaks.

Photo Copyright 2010 by Barry Fackler

Looking at the animal head-on in this photo, you can see that on the left side, the mantle is almost all the way up, while on the right side a good part of the shell is exposed. Note the bright white line down the shell's center. This is the point where the two halves of the mantle meet.

Photo Copyright 2010 by Barry Fackler

In this last photo you can see the "spiky" appearance the papillae give the cowrie. These projections serve a sensory function giving the snail additional information about its environment.