The yellow longnose butterflyfish has an 'eye-spot'.

German Oceanographic Museum, Foundation German Oceanographic Museum

German Oceanographic Museum, Foundation German Oceanographic Museum

The friend of the coral with a false eye

When this striking representative of the Butterflyfish is making its rounds through the tropical aquarium, its second, more commonly used name is not surprising: it is called the Copperband butterflyfish after its horizontal orange stripes. Like all butterflyfish, this coral resident has a long, pointed snout and a tall, flat body. Both are ideally suited for narrow, deep crevasses in the coral reefs, where it has specialised in certain types of polyps and tubeworms. He also likes to eat small crabs in the sand. The Butterflyfish leaves the reef-building corals unscathed, however – a practical cohabitation.

The aquarists at the MEERESMUSEUM also like to make use of this situation. Both reef inhabitants are kept together in one tank. The corals are protected against the Glasroses, unloved sea anemones, which multiply quickly and en masse and threaten the coral heads. Using Butterflyfish againt the aquarium pests is the solution. If, however, they get their special food rarely, there can be problems with keeping. It is difficult to accustom these fish, which are considered to be extremely sensitive, to replacement feed.

But the Butterflyfish has yet another interesting special feature. In addition to their bright colours, large, black eye-spots are visible above the root of the tail. An apparent false eye, which is there to confuse predators regarding the correct end of the body. The fish can dodge a possible attack from the rear at the supposed head with a quick escape forwards.

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  • Title: The yellow longnose butterflyfish has an 'eye-spot'.
  • Location: Deutsches Meeresmuseum, Stiftung Deutsches Meeresmuseum
  • Rights: photo: Johannes-Maria Schlorke