Unless you have what I consider a large aquarium (I clean tanks for a living. Large tanks require getting inside!) the only species suitable for aquaria would be Esox americanus, either the Grass or Redfin Pickerel depending upon subspecies. They'll only reach about a foot long, while Chains will get twice that size. My probable hybrid (the ranges overlap in the FL panhandle where mine was caught) has been in my care for just over a year, and has grown from about 1.5" to about 8". It's still in the 40 breeder (36"L x 18" W x 16" H) I raised it in, but a 180 (72" L x 24" W x 24 H) is almost ready. As far as tankmates, most people have a very mistaken impression about Pickerel. The see the teeth, consider that they eat other fish and think they're aggressive. Nothing could be further from the truth. A Pickerel is the most peaceful fish in the world. To anything it can't swallow. If it can swallow it, it won't last long enough to get beaten up! Far more likely that other fish will beat on the Pickerel, or outcompete it for food. Mine shares its tank with a 3" Green Sunfish and a 6" Yellow Perch. I removed a 4" Bluegill and a 3" probable Greengill a couple of months back due to them getting a bit pushy at meal time. Fwiw mine ate only live fish for the first couple weeks. It was a pain having to pick out the smallest feeder Guppies for it! I got it to take dead fish, and eventually it even learned to take properly presented pellet foods, but the pellets are for the Sunfish and the Pickerel just learned that whatever hits the surface of the water is food so he started grabbing them on occasion. Pickerel need a fairly large tank for their size, because although they stay motionless 90% of the time, when they do move they mean it. If people ever invent the technology of teleportation, the first traveler will be met at his destination by a Pickerel smiling a toothy grin and saying "what took you so long?"! My rule of thumb for fast moving fish is that the shortest side of the tank should be at least twice the length of the fish. The longest side should be as big as you have room and a budget for.
Edited by Subrosa, 12 May 2013 - 01:11 PM.