Scissortail Dartfish
An open-water dartfish, pale grey-blue at the front and shading to dark blue-black at the rear, with tall fins it flicks constantly while hovering into the current. It sits in the middle of the tank picking plankton rather than sitting on the rock, so it wants open swimming space plus one rock crevice it can bolt into — that crevice is what makes it settle and stop hiding. It is peaceful with everything and reef-safe. The single thing that kills them in home tanks is jumping: they leave through very small gaps, usually at night, so a sealed lid or full mesh screen is required. Also sold as the Blackfin Dartfish — WoRMS gives that name to this species, not to the Blacktail Dartfish.
Tankmates
How Scissortail Dartfish gets on with the rest of the reef, checked pair by pair by the same engine as the live pre-flight.
Best kept apart
A real clash — aggression, predation or a same-genus fight.
Keep an eye on these
Usually fine, but worth watching in a smaller tank.
Good tankmates
No conflicts — a few popular ones to start with.
