Well, Kuroaitou asked in chat who could do some testing on antimatter + shields, and I was bored, so I decided to test some different shields.
4vg 6ts 6ts 6ts 6ts 6ts 6ts 6ts 6ts 6u3 6u3 6u3 6u3 6u3 6u3 6u7 6u7 6u7 6u7 6u7 6u7 6ug 713 7n0 7n8 7qb 7qb 7qb 7qb 7t8
6ts 6ts 6ts 6ts 6ts 6ts 6ts 6ts 6ts 6ts 6u3 6u3 6u3 6u3 6u3 6u3 6u7 6u7 6u7 6u7 6u7 6u7 71b 749 7n8 7qb 7qb 7qb 7qb 80d
Gravity Shield: Watch the antimatter FFQ is blocked, the antimattered firefly isn't.
Phase Shield: Everything is blocked, also the antimattered creatures
Wings: Antimattered non-airborne creatures can't hit (first squid), antimattered airborne creatures still heal you.
Dissipation Shield: Antimattered creatures heal you, other creatures soak up your quanta.
Dusk Mantle/Fog Shield: They have no effect on antimattered creatures. (at least, not in the 6/7 turns I checked)