The black banded bamboo shark is a member of the cat shark family. In the wild it can reach to almost five feet and is a bottom dwelling shark. It feeds primarily on crustacea, small fish, and cephlapods. It has the ability to 'walk' on its pectoral fins and therefore can crawl into tight spaces to retrieve food. It is best to feed them atleast three times a week to satisation. The banding on the young will usually fade when the animal reaches adulthood.
One problem you will encounter with the bamboo shark and a 125 is the footprint of the tank. Either standard size 125 will have a footprint that is too small for the adult bamboo (which can reach well over three feet in captivity). I would also strongly agree with MorayM as to the filtration needed for proper shark care. Sharks are very messy eaters and here is the rub, they also require near pristine water conditions. This can be accomplished, of course, but requires the largest bio-filter, protein skimmer, and dedicated water changes. Live rock is an option but special care must be given to how it is used. I would not recommend using LR as the sole biological filter. Even with the best LR there just isn't enough surface area to filter a shark tank.
I would highly recommend a larger tank for any ray. These guys need lots of room to swim and hunt for food. It is very unnatural for most rays to spend all its time in one place. I would have to agree that an 8x3 is the minmum for any ray.
There is one option you could try but not sure how it'll go over. You could purchase a round water trough such as a Rubbermaid and use this as your tank. The round shape helps with the swimming of most elasmobranchs and being made of plastic drilling holes for overflows and the like is relatively easy.
