Stomatopod Log Entry: Short narrative of a stomatopod fight (March 29, 1998)
Contributor: Alan San Juan (Airlan)
The pugnacious nature of the mantis shrimps can get them into trouble just as easily as it can get them out of it. This ferocity in stomatopods is particularly noticeable when the animal is close to or in its burrow/cavity. At this time, mantis shrimps will not hesitate to attack intruders several times larger than themselves.
In the film Incredible Suckers, a gonodactylid gets itself into trouble when it drives off an extremely poisonous blue-ringed octopus from in front of its home, only to have the cephalopod sneak behind its lair and use its venom to paralyze it on its relatively vulnerable rear. In Cathedral in the Sea, a Hemisquilla ensigera gamely battles a much larger octopus and chases it away from its burrow.
I once placed a large Gonodactylus chiragra specimen (9 cm) into a 10 g tank that also contained a much smaller Gonodactylus individual (3.5-4 cm). I was in the process of preparing a small tank for the smaller mantis shrimp, and I decided that I could leave the two together for the short time it would take me to test the water of the new tank. In addition, the smaller mantis occupied a snail shell that would have not been a viable home for the much larger individual, and so I expected no home grabbing to occur. I also placed other hiding places in the tank for the new resident, and the 9 cm specimen slipped into one of these after a short while.
I had been away from the tank for a scant 5 minutes, when I noticed that the larger mantis had come out of hiding and was moving slowly around the tank. Before I could move forward, it reached the front of the other's home shell. The larger mantis was quite involved in exploring the surface of the tank glass walls, and the thought that went quickly through my mind was that it would pass across the area with no problems.
To my horror, the small mantis shrimp suddenly appeared from within the shell and exploded out of its home to strike with its raptorial appendages. I could hear the crack of its strike, but I had no idea whether it actually managed to hit the other animal. The next 5 seconds or so became a blur, with the larger mantis striking at the shell and driving the smaller mantis shrimp from its home, then chasing it. I could hear one or two cracks as I rushed towards the tank. The things were moving so fast I couldn't really see the strikes, or the mantis shrimps clearly for that matter, and I had visions of the smaller mantis becoming as one with the larger stomatopod's massive "fists".
When I got near the tank wall, I noticed that the larger stomatopod had curled its telson (rear portion) forwards in the typical "defensive" reaction of most smashers. I rapped on the aquarium walls and scared it back into its hiding place, then looked around for the smaller mantis.
The little thing had perched itself atop one of the plastic decorations littering the aquarium. If you've ever seen a dog sitting with its front paws stretched out in front of it, then you have some idea as to how it looked at the time. It seemed to be so composed and calm that you wouldn't believe it had been involved in a deadly fight just a few moments before. The scene actually made a pretty "cute" picture, but I had a devil of a time catching the small mantis and placing it into its new tank.
Fortunately, it seems to have escaped from that encounter with no problems, and is still thriving in its new home (another large snail shell without any anemone).
Web Site Author: A. San Juan
Site Created February 3, 1998