Dartfish
Blacktail Dartfish
Ptereleotris heteroptera
A slender, pale blue dartfish with a yellow-marked tail that hovers gracefully in open water above the sand, darting for a rock crevice at the first sign of trouble. Completely peaceful and reef-safe — it ignores corals and inverts — and looks best in a small group cruising the mid-water together. It is a champion jumper, so a tightly fitted lid is essential, and it wants open swimming room alongside plenty of bolt-holes.
Best in a group of 3+.
Something look wrong? Report an errorTankmates
How Blacktail 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.
