you could also buy a marble some of them seem to mature faster and stay smaller and buying a male they will usually stay smaller than females so if you can find a mature marble at 8 or 9" then i think he will be able to stay in that tank for a good time. but alot of rays will outgrow that tank. i think hystrix will stay the smallest but if you just want one then get a male as he will stay even smaller. the stickies on the top of this forum will tell a general size chart. and you could do some research and see who has what type of ray and ask the owner there experiences with how fast they are growing and how long they will be able to stay in 2' tank.
