2007-07-18 08:35:23 · 18 answers · asked by TINKS 1 in Pets ➔ Fish
They are molluscs that branched off in evolutionary terms some time ago. A slug is a different species from a snail. Your question is the same as asking, 'why do stick insects not have roots?'
Physical similarity is not a measure of evolutionary closeness, for example, and I could be wrong here, but I'm sure the closest cousin of the whale is the cow.
A slug is as evolved as you or I, its just it happened not to evolve a shell; or for that matter legs, hooks, wings etc
2007-07-18 08:44:23 · answer #1 · answered by Anonymous · 2⤊ 1⤋
well... this is a very good question. In the beginning there were no such things as snails, but as the slugs became more violent they started to attack hermit crabs. They then, stole they shell like a pikey and thats where snails come from :)
2007-07-20 10:27:43 · answer #2 · answered by Cambridge Aquatics 4 · 0⤊ 0⤋
If snails are threatened they can retract into their shell for protection. Some slugs have a poisonous slime and if they are eaten???? Dogs can become very sick if they eat slugs.
2007-07-21 12:28:55 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Oddly enough, the evolution theory is nearly right - except that slugs evolved FROM snails to fill a different niche - some of them actually have ghost shells, small hardened areas on their backs where the shell was.
NOT that I know this from personal inspection you understand, the nearest I get to either of them is when I stomp on them!
2007-07-18 15:55:55 · answer #4 · answered by Hedge Witch 7 · 1⤊ 1⤋
they evolved to fill a different niche,
for one reason or another snails need shells and slugs don't. probabaly because snails can live further from water than slugs can and the shell holds in water better, allowing better diffusion of O2 over their gills (yep snails HAVE gills) in dryer environments.
2007-07-18 15:40:26 · answer #5 · answered by Anonymous · 2⤊ 2⤋
snails are hard slugs are soft touches
2007-07-19 11:21:13 · answer #6 · answered by ken p 5 · 1⤊ 1⤋
because snails need to be in shells for cooking but who would eat a slug
2007-07-18 15:46:20 · answer #7 · answered by wifey 2 · 0⤊ 3⤋
Some slugs do have shells but they're snails. And some snails don't have shells but they're slugs.
2007-07-18 15:48:21 · answer #8 · answered by shane c 2 · 1⤊ 3⤋
Because slugs are homeless snails!
2007-07-18 15:37:17 · answer #9 · answered by K8 3 · 0⤊ 3⤋
they just evolved in different ways. they addapt to their enviroment and in order to do thst they have to evolve. i would guess becuase slugs evolved a protective slime that keeps animals from eating them and snails evolved shells for the same purpose. hope that answers your question
2007-07-18 15:57:20 · answer #10 · answered by Anonymous · 0⤊ 0⤋