Yes to the above two. Some can keep different strains together no problems, while others find that they do not play nice. Up to the keeper to decide if different strains are friendly to each other or not.
Very true. I have 2 gbta's with orange tips, 1 bright green bta and 2 rbta, plus other nem species.
They were all separated in different locations in my tank. When I introduced a new rbta to my DT, it decided to find a spot where it was literally hanging upside down under an arch. I never fed it because it was impossible to get to. After about 1 month it decided to move to a new spot, presumably becasue it felt the chemical scent of food, but never actually got any. It moved close to an orange tip gbta that was about 3 times it's size. I noticed it moved only when I got up in the morning when I checked my tank. I left it alone thinking it would be fine, but to my surprise it shriveled in about 2 days in a way that looked like for lack of better description 'burnt'. The tentacles on the side where it was in contact with the other gbta were reduced to stubby protrusions. Over the next few days it closed itself completely giving me the chance to reposition it in a better location. It took about 2-3 weeks to start recovering and accept feeding.
Now it's fully recovered and about 4 times the original size.
Interestingly one night my large gbta decided one night to move a few inches next to the once injured rbta. I kept a vigilant eye just in case I had to intervene again. Tentacles were touching frequently, but nothing happened.
So, long story short, as others stated the right answer is yes and no. You will have to keep a close eye to ensure if they are friendly to each other or not. In my case, this rbta was 'allergic' to my orange tip gbta's but fine with the other roses and green.
