Which conch?

[Fishfreak2009]

Purchased 2 conchs today as florida Fighting conchs but one has a different style of growth for the spikes on the shell. They are much larger and appear more flattened. Does this look like a juvenile queen conch and not a Fighting conch?

The fighting conch

The conch in question

 

[WheatToast]

Milk conch (Macrostrombus costatus)? Wikipedia says they grow up to 7 inches long and that they feed on algae. I've seen them on Diver's Den as well with symbiotic Conchfish (Astrapogon stellatus).
https://www.kpaquatics.com/product/milk-conch/