WHY DO SNAILS HAVE SHELLS AND SLUGS DONT?

[ihavequestions]

WHYYYYYYY

 

[viper69]

No one knows why per se

It’s like asking why snakes lost their legs.

 

[DomGom TheFather]

 

[Snailientologist]

Slugs evolved from snails who gradually shrank and internalized their shells. Many modern slugs still have traces of shells covered by their skin. The loss of shells provided them an ability to crawl into tighter spaces and to survive in low calcium environments. Oddly enough, this transition happened several times(at least 22). In some species, the introduction of platinum can halt shell production entirely, turning baby snails into creatures that by all means resemble slugs.

 

[Coradams]

They prefer to travel light.

 

[Arthroverts]

An excellent question. I would say some micro-evolved to be that way, others were created that way, giving us a very interesting milieu of terrestrial (not to even mention aquatic) gastropods to study.

Thanks,

Arthroverts

 

[schmiggle]

Slugs evolved from snails who gradually shrank and internalized their shells. Many modern slugs still have traces of shells covered by their skin. The loss of shells provided them an ability to crawl into tighter spaces and to survive in low calcium environments. Oddly enough, this transition happened several times(at least 22). In some species, the introduction of platinum can halt shell production entirely, turning baby snails into creatures that by all means resemble slugs.

Has anyone ever compared the calcium in snail and slug microhabitats and/or diets? I did read that there's a species of subterranean snail that tends to occur in high calcium environments.

I will say, with regards to the other point--all of the snails I'm aware of that are subterranean or found in and under logs are tiny, whereas slugs can be sizeable. I regularly find slugs several inches long in logs, but I've never found a snail above about half an inch in length in a log. I don't know if this holds up to statistical scrutiny, though.

You're only asking about terrestrial slugs, right?

 

[Smotzer]

Slugs are ascetic snails, they left comfort and their homes behind

 

[Coradams]

Slugs are ascetic snails, they left comfort and their homes behind

Are you saying that slugs are just snail minimalists? lol