Pomacentridae

Whitetail dascyllus

Dascyllus aruanus

Black white schools above staghorn corals

• Black
• White
• Tropical
• Regional distribution
• Marine fish
• Indian Ocean
• Pacific Ocean
• South Asia
• Compressed
• Compressed cross-section
• Small
• Tropical fish

Bold black and white striping gives the whitetail dascyllus an instantly recognizable presence around shallow branching corals. Three prominent black vertical bars cross its pearl-white body: the first running from the nape through the eye to the chin, the second descending from the mid-dorsal fin to the pelvic fins, and the third banding the rear flanks. Its tail fin remains completely white or translucent, an essential field mark distinguishing it from the four-striped humbug. Native to the tropical Indo-Pacific, its range spans the Red Sea and eastern Africa across northern Australia to the Line and Tuamotu islands. Social colonies inhabit lagoons and sheltered reef crests down to twenty meters depth, tightly associating with Acropora and Pocillopora coral heads. At the first sign of danger, entire schools dart deep into the interlocking coral branches for safety. They feed actively during daylight on planktonic copepods, small amphipods, and benthic algae. Males clear a patch of coral base, court passing females, and vigorously aerate the deposited demersal eggs until hatching. Maximum total length is approximately ten centimetres.

Sources: Australian Museum — Humbug, Dascyllus aruanus