From
this thread I can tell what the different types do, but I'm not sure what all their symbols look like.
This list is taken from the link up there.
- Electrical – Stuns targeted enemy and nearby enemies for a short period. The burst of electrical activity will short out the Heads Up Display provided by the ego for this duration.
- Incendiary – Lights targeted enemy aflame, harming him for a short period of time.
- Biological – Attaches biological compounds to a target, slowing them down and causing them to do less damage for a short period of time.
- Radiation – Irradiates the target, weakening their armor and causing them to take more damage from attacks for a short period of time.
- Syphon – Steals health from the target and transfers it back to the shooter.