Is this an astrae or trochus snail?

[gordoncheers]

As mentioned in the title

 

[TX_REEF]

Trochus.

 

[gordoncheers]

Trochus.

How can you tell them apart?

 

[Science/G]

Astrea snails have white cone shaped shells for the most part

 

[TX_REEF]

How can you tell them apart?

Trochus move faster, can right themselves if they fall upside down, and generally have darker shells with a less pronounced point at the tip, the shells are a bit more flattened. They also have little stringy appendages that radiate from their flesh kind of like rays of the sun in a kids drawing. Finally, they readily breed in our tanks, so if you see baby snails appear apparently from nowhere, that is likely the culprit!