THE LIONFISH IS A VERY COMMON SPECIES, and every diver who visits the Red Sea will be familiar with it, and able to identify it. Most divers know the basics about lionfish, too. They are voracious predators, hunt mainly at night, and the venomous spines on their fins discourage novice divers from getting too close and flapping their hands about.
This January, however, I was lucky enough to witness a couple of these fish engaged in some more unusual behaviour.
It was mid-morning, on a clear sunny day, when lionfish are normally resting on the reef or under overhangs after a night of hunting. Two were apparently locked together, cheek to cheek, fins erected in a defensive posture.
They pushed against each other, spinning and tumbling through the water. Even when they collided with the reef, this did not deter them.
The duel continued for several minutes, and the fish covered many metres as they moved away from the reef wall, over some fan corals and into the blue, away from the safety of the wall.
Throughout the incident they seemed oblivious of either me or the other divers who came by to investigate. I eventually left them, and rejoined my dive group.

I WAS UNABLE TO FIND any other photographs of this behaviour when I searched later, and not many clues as to what was going on. Courtship and mating is not known to take place during daylight hours, and neither fish appears to be full of eggs, so this probably does not explain it.
The most likely explanation, according to Stephanie Greene, a marine biology student from Simon Fraser University in Vancouver who is doing research on lionfish in the Bahamas, is that they were two male fish in a territorial battle.
During the mating season, males are reported to become darker in colouration around the head and pectoral fins, become more aggressive and circle each other in the water column.
I dont know which fish won the battle, but when I returned about an hour later, what I guess were the same two lionfish were both resting under an overhang, a couple of metres apart, not far from where they had been wrestling.
I guess, as with most human conflict, there was no clear winner in this battle.