Nassarius snails are much smaller in maximum size than turbos. Nassarius max out at about 1/2 in. Nassarius max out at more than an inch. Trubos have a conical shape wheras nassarius have a more ovular shape. Also, Nassarius will bury themselves in the sand looking for a meal,a dn the turbos really like to stick to walls and rocks. Nassarius also will graze on the walls and rocks. The only nassarius I have ever seen are dark grey to black in color only. Turbos can come in red as well as white, grey, adn black most frequently. Post a pic.