Blacktail butterflyfish

The blacktail butterflyfish (Chaetodon austriacus) is endemic to the Red Sea: blue-black horizontal lines run along its orange body, while the tail fin, anal fin and rear dorsal fin are deep black – hence the name. A dark bar through the eye and a compact, rounded body complete the look. You can tell it from similarly patterned relatives (such as Chaetodon trifasciatus) precisely by that fully black tail fin.

This species is an obligate corallivore: it feeds almost exclusively on the polyps of living hard corals, so it can only survive where the reef is healthy and coral cover is high. For divers this makes it a living indicator: wherever you see pairs of blacktail butterflyfish, the reef is doing well. The pairs are strictly territorial, defending their coral garden together against intruding rivals and working their way through the polyp colonies slowly and methodically.

Fortunately Hurghada's reefs are in good shape, so you meet this endemic beauty regularly: it is common in the Gota Abu Ramada coral garden, on the Giftun plateaus and along El Fanadir. Since it favours shallow, coral-rich reef tops, you have a good chance of watching it while snorkeling too, typically between 1 and 15 metres.