29 October 2010

A well sealed snail shell


I mentioned in this recent post that I was working on a method to measure the volumes of snail shells and that I needed a way to seal their apertures against water. After tape, chewing gum and plasticine failed, my wife came to the rescue and suggested silicone ear plugs. I tried them tonight and got good results. The shell in the picture was sealed with silicone. The main drawback is that the application and removal of silicone is time consuming.

Results are forthcoming.

9 comments:

Julia said...

I like that bright orange color too!

Kevin Zelnio said...

Doesn't it work if you stretch a bit of parrafin over the aperature?

I used to seal cracks with a glue gun and stretch and press parrafin over the aperature. My snails were up to fist sized though so it wasn't too difficult.

AYDIN ÖRSTAN said...

The problem is getting parafilm stick to the parietal wall of shells. Otherwise even the films used for wrapping foods would work.

Kevin Zelnio said...

Why do you need to seal it anyways? I would add a little bit of water and twist it around to get around the whorls, then keep going until I filled it up to the aperature.

Of course, the trick was making sure you got ALL the back out. Pain in the ass, thankfully I had undergrads.

Kevin Zelnio said...

This is unpublished work, and used to determine AFDW/Volume ratio as a condition index. The index failed though, because well... snails can respond to changes in their microhabitat by crawling away. Works great on mussels though.

AYDIN ÖRSTAN said...

How do you know if you have filled a shell all the way up to the apex when you can't see the inside?

DPC said...

Is it possible to somehow perforate the protoconch and draw water up through it, then seal it again? That way the problem of air bubbles could be eliminated.

AYDIN ÖRSTAN said...

It can be done if you don't mind ending up with perforated shells. You will also have to figure out a way to seal the holes.

Jan-Maarten said...

Wouldn't gelatin work? You'd have a perfectly flat surface sealing the aperture, and to clean you'd just reheat.