11 May 2008

Dissection of Truncatella caribaeensis - Part 1

This is the 1st time I am dissecting a Truncatella specimen. In fact, this is the 1st time I am dissecting a non-pulmonate snail. Perhaps, I should have started off with a bigger species, but I need to learn about the anatomy of Truncatella for a research project and I don't want to waste time dissecting specimens that are not of interest now.

TruncatellaDissection1
Preserved specimen of Truncatella caribaeensis. The arrow points at the operculum.

The shell of this particular specimen of Truncatella caribaeensis was about 6 mm long. Since it is difficult to break apart the shells of such small snails without damaging the tissues inside, they are best eliminated by dissolving them in dilute acid. The carbon dioxide bubbles generated from the reaction of the shell material with hydrochloric acid proves that the shell is indeed made of calcium carbonate, in case there was any doubt about it.

TruncatellaDissection2

Here is the snail's body left behind after almost all the shell dissolved away. The arrow labeled m is pointing at one of the defining organs of the phylum Mollusca, the mantle (occasionally also referred to as the pallium). The snail's body is protruding from the mantle cavity, the space below the mantle. This proves that T. caribaeensis is indeed a mollusk, in case there was any doubt about it.

TruncatellaDissection3
m: mantle, t: tentacle; s: snout; f: foot. The scale is in millimeters.

Now I will start the actual dissection. If I don't botch it, I will write about it in a future post.


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