These fish often starve in captivity. Even if they eat prepared they often wither away and die. They eat WAY too much for a tank to keep up with. Even in the largest of tanks they often decimate the microfauna in the sandbed. Their food source is only in the sand, they don’t get it anywhere else. Here’s something I wrote in a post about the family “Gobiidae”.
“This is why I didn’t add Valenciennea, I was going to but they really aren’t good for a tank unless they’re in a 5-6 year old tank.
Most of the time Valenciennea will wither away and die - I have been debating one in my 2 year old 4’ tank but still don’t know if I’m willing to. The reason why many Valenciennea species wither away and die is due to what they use the sand bed for. These gobies could be worse than dragonets to keep, they use the sand bed to sift through and find microfauna like amphipods and copepods. The young (<2 year old) tanks can’t sustain these long term because they don’t have the micro fauna to forage in. Valenciennea gobies are known as the “sleeper” gobies, so I’d recommend avoiding them unless you have a 2 year old or older tank. These also need rather large tanks, they’re more active than the average goby and get 4 inch, in many cases 5-6 inch. I’d probably say a 3’ tank is pushing it for the minimum tank size, 4’-6’ would be best IMO.”
