Spiral shells

[paigetheoracle]

Do all snail shells spiral in the same direction i.e. clockwise or is it dependent upon species, or whether they exist in the Northern hemisphere or The South? (Thinking of the way water drains away in opposite directions, depending upon whether it's north or south).

[freeztar]

Do all snail shells spiral in the same direction i.e. clockwise or is it dependent upon species, or whether they exist in the Northern hemisphere or The South? (Thinking of the way water drains away in opposite directions, depending upon whether it's north or south).

 

It depends on which way you look at them. :)

[Jay-qu]

From what I remember from a high school class on see creatures, you are most likely to find shells in one direction only - but a rare mutation can make them grow the opposite way. We were promised $50 for any of these 'reversed' shells we could find (I cant remember if it was clockwise or anti-clockwise that was abnormal..)

[Qfwfq]

But JQ snail shells have a plane of specular symmetry (as Freez points out).

 

Thinking of the way water drains away in opposite directions, depending upon whether it's north or south

Gosh, surely they don't get effected by Coriolis, he was a quick fellow who would never have the patience to wait for snails and the likes.

[paigetheoracle]

But JQ snail shells have a plane of specular symmetry (as Freez points out).

 

Gosh, surely they don't get effected by Coriolis, he was a quick fellow who would never have the patience to wait for snails and the likes.

 

So what is specular symmetry?

[Eclogite]

Do all snail shells spiral in the same direction i.e. clockwise or is it dependent upon species, or whether they exist in the Northern hemisphere or The South? (Thinking of the way water drains away in opposite directions, depending upon whether it's north or south).

Snail shells may spiral in either direction. It has nothing to do with the hemispheres. (The water draining down the plughole is an urban myth. It doesn't work that way.) While one species may have a preference one way or another, the same species can have both spirals. The direction of spiral is determined is inherited from the mother.

The sex organs are oriented in relation to the spiral so it is difficult to achieve this for snails having different spirals.

[Qfwfq]

So what is specular symmetry?

Er, I dunno but I'd speculate that a spectre looks the same if you see it through the looking glass... :)

[Jay-qu]

From http://findarticles.com/p/articles/mi_m1200/is_16_164/ai_110459320/

 

For most species of snails, shells and body plans curl in only one direction.

 

If a random mutation flips the direction of spin then the snail will be pretty screwed when it comes to mating.. This article speculates that a few times in history such a mutation could spawn a new species as if you get a few mutations at once, they will be cut off from mating with the rest of their species.

[Qfwfq]

So far I've never seen a snail that was a neutrino. That article doesn't have any pictures. What do they look like?

[Jay-qu]

Ok so it is hard to see on your typical garden snail, but on this one you can clearly see the 'handedness' of the shell:

http://etc.usf.edu/clipart/6900/6964/snail-shell_6964.htm

[Qfwfq]

What a crooked critter! :lol: