Marine marvels: Do you keep uncommon fish in your tank?

[i cant think]

What species is the blue one at the end? Never seen one before.

That was my first Hoplolatilus chlupatyi, my second vanished without a trace a few months ago.
They’re a PITA to come across and even harder to have thrive in a tank as they’re rather jumpy and a lot of the time have swim bladder issues.