The poison was just supposed to be physical, since its engineered purpose was to pacify animals being fed upon. But mental stunning is fine too.
If anyone is still hanging around this thread, there were a couple other issues that came up in designing this racial package. Would having a vocal range greater than a human, in other words having the ability to make higher and lower sounds, be an advantage that would have to be paid for? I'm also having some trouble understanding the rules for lighting and darkness. This species is supposed to have the ability to glow when it's dark. As near as I can tell, this is supposed to be bought as image with the limitation that it can only create light. What I can't figure out is how this is supposed to affect the sense rolls of other people that are around. There is a bonus to spotting the light source itself, but it doesn't seem to illuminate nearby objects and make them easier to see.