Fighters are sneaky little critters. I had some cherry shrimp in with my group of fighters and quickly removed the shrimp after I saw one of the girls hunting the shrimp down. Months later I saw more shrimp still happily roaming about the tank, they must have been bubs that grew up in there and knew to stay in the thick the moss. There is 6 otocinclus in the tank that the fighters have never even shown the slightest interest at.
Fighters will it seems get a preference for certain other aquatic friends, but if you try to give them a similar one they will decide they don't really like the new tank mate.
I don't know what is going on with my rili shrimp. I know I have one female I see her sometimes swimming about with a saddle and I know I have two males because I have seen them both at the same time. But I can see no evidence of them actually breeding or more shrimp appearing in the tank. The tank does have a jungle of moss so maybe they are breeding up in there, but I also have the sinking suspicion that the endlers in the tank are eating the smaller shrimps they come across.
Good news on the Barney Springs shrimp I got from up north. I was a bit worried that they had slowly died off since I almost never see them in the 4ft cory tank jungle ( I swear I could have an aquatic tiger in that tank and not know about it), and so I thought I would do some rearranging of some of the plants. As soon as I moved the massive java fern I had shrimp shooting out all over the place. I then took the timber and java fern over to another bucket of water while I thinned and reattached the fern. Just as well because when I had finished at least another 20 shrimp had hitch hiked over and where feeling lost in the tub of water. So it appears that my water seems to suit these native shrimp, now I just have to see if they can survive our summer.