BlattaAnglicana, sorry, I know this is a late reply, but I wanted to chime in, and check in to see how your colony is doing and how the nymphs have grown?
I was reading on a FAQ site that a professor that works with roaches posted (started posting research papers on roaches back in 1966) and unless I'm confusing my source, he doesn't think roaches have the brain capacity to feel and remember pain as humans do, so even if this female may have seemed to suffer by human terms, chances are good that she didn't actually suffer from her perspective.
I'd guess the female that died was much older than the seller said. I don't know about hissers directly, but you can't really tell the age of an adult roach unless you separated them out as nymphs and knew when they became adults, and chances are he/she just pulled these out of the colony and they had no real idea of their age. I may be wrong, but how many people have the room to store bins of roaches based on their ages so they know for certain they are selling younger stock?
Has the other female been successfully breeding for you?
I believe I also read that if you want to view your roaches without causing them to run away, use a black light or infrared light. I don't believe they are able to really detect either. I've not tried either, but infrared is outside our human scope of vision, but if you pull out your cell phone camera, the CMOS receptors that capture the light for pictures should be able to see the infrared light. It may look like an episode of 'Ghost Hunters' in black & white grayscale though.
Here is a good FAQ on roaches from the University of Massachusetts. I found several of the Q&A very interesting.
http://www.bio.umass.edu/biology/kunkel/cockroach_faq.html
A few questions I found interesting:
6.Why do cockroaches die on their backs?
7.Do cockroaches bite? (actually, they do...they eat about anything that doesn't move or fight back)
12.Are cockroaches really clean? (yes...and no. They keep themselves very clean, but still walk through poop and such)
39.How do Cockroaches Digest and what organs do they use to do so?
56.How fast are cockroaches? (did you know that roaches run away from air movement near them as a built in defensive reaction, no brain response involved!)
68.Color cockroaches most attracted to?
79.Can female-only set of hissing cockroaches give birth 7 months after purchase?