The last time I was in Walmart, I nearly threw up when passing the fish area. Even more sickening, was that a bottle of Ich treatment was still on the wet counter. Dead fish in every tank with live ones pecking away at them.
There should be some way of collectively complaining enough to get something done. I've seen this in other states too. I travel a lot, and I've seen the same things in at least four states-- just from happening upon the fish area at the same moment I happened to be at WalMart. Random times, random dates-- 'ya know.
Start with the store manager, not the department manager. This will get visibility on the problem from the position that it needs to come from. Mention health hazard, unhygienic, disgusting and deplorable as many times as you can in the conversation. Check back in a few days later to see if the problem is fixed.
If it is not then get the store number (you can find that on one of your receipts in the top few lines) and the store managers name. Call 1-800-WALMART and relate your story to them. Recount the number of times you complained an the lack of attention that living creatures are receiving, this is also a good time to mention unhygienic as many times as possible. Have others call in as well, this is the number to the corporate headquarters in Arkansas.
Corporate will yell at the regional manager about unsanitary conditions and unhappy customers, who in turn will come down to your store and yell at the store manager about it.
If you do that, one of two things will happen.
1) That store will force its employees to do their job and maintain the tanks.
2) The store doesn't keep things clean. You keep calling 1-800-WALMART and complaining. Eventually corporate will be forced to shut down the sale of live animals and will sell only tanks and other dry goods.
This is how several of the Wal-Marts around the area where I grew up stopped selling fish. Corporate doesn't like unhappy customers, so if they will do what is necessary to keep you shopping there.