Trumpetfish

One species in three tiers: the Caribbean Trumpetfish (Aulostomus maculatus). It is a long, rigid tube of a fish that hangs vertically among gorgonians and rock, holds that pose for hours, then closes the last few inches on prey in one motion. The display is the stillness, not the swimming.

What it eats is other fish. A trumpetfish takes anything small enough to fit down that snout, and the snout is longer than it looks, so gobies, small wrasses and juveniles are food rather than tankmates. Keep it with fish it cannot swallow, or keep it alone. Shrimp are not safe either. The three tiers differ in how long a fish has been watched before it leaves; the comparison is here.