I wound up getting 10 in total. I have them in a planted guppy tank and they all seem to be doing well. The biggest is about 4 1/2" and the runt is about 3 1/2". They seem to be picking off the baby guppies and the males. They don't seem to bother with the larger female guppies. Every couple of days I give them some of the Hikari sinking carnivore pellets, shrimp, or whatever fish is on sale at the supermarket. By day you don't even know their in the tank but around 10-11pm they all start to become active. I have a moonlight on the tank so I've been watching them hunt and know why they are called ambush hunters. I've been reading on planetcatfish.com about breeding but have only found articles on microglanis. No luck yet on breeding but I'm starting to notice some distinct differences ie head and body shape, and coloration. Don't know who's who yet. I have noticed that a few of them seem to always be together. Can't really say if they are paired up or just coincidental. I've been trying to get some good pics but no luck. I get a black blur. I got to set up a tripod I guess.