Nerite snails are small intertidal snails. These make a good addition to your clean up crew, especially if you have a lid on your tank, as these guys sometimes like to crawl out of the water. They are very hardy, eat algae and detritous, and also have colorful black and white shells. Some (may be a slightly different species) have hints of red, yellow and blue in their shells. Sold as singles, or in lots.