ORA writes:

Sometimes the best camouflage requires no color at all.  The Transparent Cave Goby is a translucent fish with orange spots on their flanks and a blue sheen in the unpaired fins.  Their internal organs and skeletal system are visible under aquarium lighting.  This fish reaches 3” in size and they are typically found confidently hopping among rocky rubble, protecting their territory and hunting small crustaceans.  They are not picky eaters and will consume pellets and frozen food. While they are peaceful with most other species of fish, their somewhat territorial nature with conspecifics may limit how many can be kept in the confines of an aquarium.  In our experience each specimen needs about a square foot of space to call their own, so in smaller tanks they should be kept singly.  In larger aquariums a few specimens can be kept together and their posturing and territorial displays will charm both the seasoned and novice aquarist.

And where are they breeding their captive bred fish? In state-of-the-art facilities like this.  Ornamental fish breeding has come a long way!