In the eyes of the mantis

The secrets of the Peacock Mantis Shrimp

Photo: W. Schmit

Photo: W. Schmit

If you join Blue Marine Dive guides, you might have witnessed them gesticulate trying to show you something, mimicking eyes on the head, punching the water with their fists, to finally explain that the creature has disappeared in a hole. Well most likely, they were trying to show you a peacock mantis shrimp. Rare animal to see in some ocean, here diving from Gili Trawangan or Gili Air, it is not at all uncommon to see this colorful shrimp. "Mantis shrimp belongs to the group of marine crustaceans. There are around 400 species of mantis shrimps that inhabit shallow subtropical and tropical waters of the Indian and Pacific oceans. They spend most of their life hidden in the rock crevices and burrows on the bottom of the sea. They have colorful shells and body posture that resembles posture of praying mantis." (http://www.softschools.com/facts/animals/mantis_shrimp_facts/620/ )

Photo: W. Schmit

Photo: W. Schmit

One of the coolest thing in those shrimps, be the peacock mantis or the spearing mantis, are their eyes. Each eye can move independently and each eye is divided in 3 compartments, with three individual iris. This means that each eye is like three eyes! It is known to be the most complex eyes in the animal kingdom, and one other crazy fact is that they can see ultraviolet and polarized light. One experience was done with a peacock mantis shrimp in an aquarium with two tunnels. One of the tunnels had polarized light and if the shrimp went there it was given food. It quickly learnt that choosing the polarized side meant food, and repeating the experience in different setting showed that it could recognize that type of light (and likes to eat!!!). Why is this interesting? Well medical research is trying to use specific lights to cure cancer. So maybe one day we will hear that the peacock mantis shrimps have helped discover the cure to cancer!

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 A second really cool fact about those shrimps is whether they are spearers or smashers. If they are smashers like the peacock mantis shrimp, then you will find out that they have a punch almost too fast for your eyes to see . So fast that it creates void. The molecules of water separates and leave an empty space. It is said to be 50 times faster than a blink of an eye, so definitely you will have to put your video in slow motion if you want to see that. Oh yes, you can also compare their punch with the speed of a .22 caliber bullet. Cool no?

At Blue Marine Dive, we like to share our knowledge about underwater creatures. If you do your Advance Course with us, you might choose to do a Fish ID Adventure dive. And with a slate in your hands, you will record all about what you see during your dive, and spend a nice moment with your instructor looking in the fish book and hearing stories about all those animals. If you are not sure about the course that you want to take, have a look on the padi website: https://www.padi.com/padi-courses/padi-course-catalog

 

To hear all that and see images as well, have a look at this:

https://www.youtube.com/watch?v=F5FEj9U-CJM

 

See you soon on Blue Marine Dive Blog, on facebook or instagram, for more cool facts or infos about the life on the Gili Islands.

All photos by our instructor/cameraman Walter G. Schmit.