The red lionfish (Pterois volitans) takes its prey by surprise inside caves

Dangerous beauty

The strikingly coloured lionfish - well camouflaged in the colourful reef - are among the most attractive fish in the tropical aquarium at the Oceanographic Museum. The front fin rays on its back contain a poison comparable to that of a Cobra. This knowledge sends shivers down the spine of the watching it through the glass, but extreme care must be taken in keeping the fish.

The poison spines are used for defence, not for hunting. When the twilight and nocturnally active lionfish hunt for prey in the open water on the reef, they form a sort of net with their large, wing-like pectoral fins. In doing so they push smaller fish or crabs into niches or hollows, so that they can then suck them in at lightning speed. In the aquarium the lionfish collect their meals at the edge of the tank. They hungrily extend the mouth open wide to the keepers.

Red lionfish are aggressive neither to divers, nor to their keepers. They are even a bit trusting. But the poison, which resides under the thin skin on the back spines, is a strong one. Harald Lüdtke from the Oceanographic Museum can confirm from his own bitter experience how painful contact is. While feeding the fish, he overlooked the spines, which were raised up out of the water one time, and touched them with his forearm. He had to be treated in the emergency room immediately. After the pain and weeks discolouration of the arm had abated, fortunately he suffered no permanent damage.