1) Picture in ad is a Plagiomnium species.
2) You may have received it or star moss (Hyophila not Tortula) as I did. Plagiomnium leaves are round or eliptical. Hyophila leaves are tongue shaped when removed from stem. Best way to tell them apart is with a high power light microscope. Plagiomnium has a border round leaves etc.
3) Both are terrestrial in nature.
4) Both will grow in an aquarium. They do not have to be 'aquatic' but they are good aquarium mosses in the right conditions: High light, CO2, frequent water changes, a little ferts