Every time I have seen Margarita snails (Margarites pupillus) for sale, they always turn out to be some unrelated species (My guess, Tegula snails). A true Margarita snail should (surprisingly) carry a pink - orange, smooth, silvery shell, not what most would normally expect from the average aquarium Margarita snail.
Examples:
Orange and pink individuals
Pink individual
Orange individual
A "Margarita snail" without such a shell might just be a fake.
Just look at this image of captive "Margarita snails": https://www.oceansgarden.com/wp-content/uploads/2020/07/margarita-cleaner-snail.png
The deep black, silvery-tipped shells resemble those of the turban (not Turbo) snails, Tegula funebralis and Tegula gallina.
The stony, coralline coated shell in the middle resembles that of the turban snail, Tegula eiseni.
Here are images of some Tegula sp. for reference: http://biology.fullerton.edu/biol317/Murray/Fall97/tegula_snails.html
Even LiveAquaria is guilty: https://www.liveaquaria.com/images/categories/product/lg_79570_MargaritaSnail.jpg
Does this confusion matter in terms of proper care for the different species though? Probably not too much. Tegula sp. and Margarites pupillus both live in similar environments (rocky shores), survive under similar temperatures (cold!), and possess similar diets (though the latter appears to be more macroalgae safe).
P.S. Reefs.com has written an article with a similar topic: https://reefs.com/2018/07/05/new-study-turbo-snails-are-the-best-aquarium-snail/
Examples:
Orange and pink individuals
Pink individual
Orange individual
A "Margarita snail" without such a shell might just be a fake.
Just look at this image of captive "Margarita snails": https://www.oceansgarden.com/wp-content/uploads/2020/07/margarita-cleaner-snail.png
The deep black, silvery-tipped shells resemble those of the turban (not Turbo) snails, Tegula funebralis and Tegula gallina.
The stony, coralline coated shell in the middle resembles that of the turban snail, Tegula eiseni.
Here are images of some Tegula sp. for reference: http://biology.fullerton.edu/biol317/Murray/Fall97/tegula_snails.html
Even LiveAquaria is guilty: https://www.liveaquaria.com/images/categories/product/lg_79570_MargaritaSnail.jpg
Does this confusion matter in terms of proper care for the different species though? Probably not too much. Tegula sp. and Margarites pupillus both live in similar environments (rocky shores), survive under similar temperatures (cold!), and possess similar diets (though the latter appears to be more macroalgae safe).
P.S. Reefs.com has written an article with a similar topic: https://reefs.com/2018/07/05/new-study-turbo-snails-are-the-best-aquarium-snail/