How to distinguish Astraea Turbo from Trochus?

[puks]

Hi guys,

I read some posts but still don't understand how to distinguish Astraea Turbo from Trochus snails in a store.


Thanks

 

[ManEatingGuppy]

easiest way to me is that trochus snails have a black body with tentacles and have red stripes throughout its shell, whereas astrea snails have a white body and have no red stripes. In addition, the ridges on astrea snails are way more defined than those of trochus.

 

[pagojoe]

There are a couple species that look so much alike you can't tell them apart by looking at the shell from above. However, the sure-fire way to differentiate them is by looking at the operculum (trap door). Astraea snails and their relatives (Bolma, Astralium, etc.) have an operculum that is made of shell material, and looks like a little pearl blocking the aperture. Trochids have a thin brown or amber disc as an operculum.

Cheers,



Don

 

[puks]

For example, this page has 2 different images. I'm confused with the top one.

 

[pagojoe]

They are both trochids. The top one is Tectus fenestratus, which looks a lot like an Astraea/Astralium, but isn't. It has the typical trochid operculum. The red-banded one is either Trochus radiatus or T. maculatus or T. ochroleucus or one of the other very similar species in the T. maculatus complex.

Cheers,



Don

 

[puks]

Is there any pictures that show this difference in the operculum?