I think that cherubfish was asking about the longnose hawk as a good nano fish... to sort of get this thread back on topic.

I have not kept a longnose before, only have observed them at the LFS and read about them, but IIRC Scott Michael recommends a 55 gallon minimum for one. They can grow to 5" in length and have a large mouth that could swallow many good nano-appropriate tankmates. I think that your best bet for a hawkfish in <35 gallons is the Falco. Its the smallest hawk and the least aggressive. I have one in an Aquapod, and it does not appear to be unhappy or uncomfortable there. It is a bit of a glutton, though, so I suppose one should watch the water quality when adding a hawkfish. The tank my Falco is in has a lot of rock in it, which gives the hawk lots of places to perch and crevices to swim in and out of. A scarlet/flam hawk may be okay in a larger nano; I'm not sure how much those guys like to swim (seems like they might like a bit more room than, say, the Falco) or how aggressive one might be if kept in a smaller tank.