The midas blenny is not as apt to bite as everyone always says and thinks. For the most part, they behave like other blennies, being fairly timid creatures, especially when encountering us human interlopers doing things like scrub downs or water changes. Exercise the same caution you would with a lionfish when you work in the tank, making sure you are always aware of his location, and keeping in mind the potential for a venomous bite.
However, when left alone, they are a bit more outgoing that other blenny varieties, often coming out for swims or patrols about the territory. Here's the rub, though, midas blennies can be bullheaded and aggressive when kept in smaller tanks, especially when their tank mates are pushovers, often nipping and biting at them to try to "evict" the undesired fish from their territory. So, in a nano-tank, 15-gallons or lower, I might just recommend the midas if kept by himself.
My manager and I used to love ordering them, keeping anywhere from one to three in stock whenever they were available. Beautifully colored animals with an absolutely strikingly shaped lyretail. Very cool blennies. We never had an issue with keeping them with other fish in 34.5G stock tanks with other species.... just not anything smaller than a chromis or pseudochromis. Any smaller than that stood a good chance of being massacred.
my fault i guess for not covering the tank.
