Cambarellus Diminutus - Also known as "Least Crayfish" and "Dwarf Blue Crayfish". Care for these are very easy and require no more than treated tap water. They do well in hard or soft water, alkaline or acidic. They do fine at room temperature as well. These breed readily in an aquarium as small as a 2.5 gallon and up. These can be kept in groups as long as there are plenty of spots for them to hide. These are plant safe and grow to an adult length of 1 inch. There are 2 known color variants - one being the brown (natural) color and the other being the Blue/Charcoal coloration. I have bred many clutches and have known that they show their best coloration as adults and get darker on each moult. Berried females really look amazing. One VERY important note is that for these to show their amazing blue coloration, they must be in soft, slightly acidic water. I have moved beautiful blue specimens from those conditions to a tank with soft, alkaline water and the coloration went to the charcoal color. The charcoal looks almost black in adult specimens. Here is a shot of one of my offspring blue morphs in soft, slightly acidic water showing nice blue color. I have these available for sale HERE