Eyes of the Mantis Shrimp – Colours and Hexnocular Vision

By Anupum Pant

Of course there’s a lot of other things to talk about the Mantis Shrimp. But today, I’m going to only talk about its eyes.


The eyes of a Mantis Shrimp are one of the most advanced eyes on the planet. To realize how extraordinary their colour vision is, you need to have some perspective on what we are talking about.

Colour is just a trick of our mind. What we see is really out there, there’s no way to know for sure if it is the reality. Or, there’s no way for us to explain what we really see.

For instance, imagine how we see the world, say particularly, the colour red and all its derived colours. Now, what you see is very different from how a colour blind person or a dog sees it. Dogs and about 10% of men who are colour blind can’t see colours like we do. That is because, instead of 3 cones (red, blue and green sensitive ones), they just have two. If you and a dog would point their eyes towards the same rainbow, both of you would see a very different image (if you are not colour blind).

A dog probably would see a rainbow which would start with a blue colour and then there’d be green in it for a dog. Nothing else. That is because it has no red sensitive cones. A single difference in the number of types cones can make such a huge difference in the colour vision. Addition of the single red sensitive cone enables us to see a whole set of new colours.

Some women (estimated to be about 2-3%of the world’s population!) have a super-human ability that makes them able to see a whole set of new colours. Like we see a million different colours, these women can probably see 100 Million different colours. It’s hard to imagine what they really see. Probably that is why they say men are so bad at colours.

Similarly, consider a butterfly. They have 5-6 different kinds of cone receptors. So, when they look at a rainbow, they probably see a range of colours between the blues and the greens and the greens and the yellows. Of course, it can also see an ultraviolet beyond the violet. Incredible enough.

mantis colour range

The Mantis Shrimp, an animal of the size of your finger, has one of the most amazing colour visions. It has 16 different types of cones. You can’t even start to imagine how the world looks to them. And suppose they try and see a rainbow, they’d see a really rich set of colours. No other animals we know have even a visual system that is half as advanced.  There’s no reason they must have this ability.16 is just too many cones!

Needless to say, these technological marvels can see ultra-violet light, infra-red light, and some can even see polarised light.

Hexnocular vision


Now, we see with our two eyes and call it a binocular vision. We have 2 eyes and 1 focal point each. So, to see in 3-D, we need both out eyes.

Mantis Shrimp, however, has 2 eyes with 3 focal points each. Each of its eye is divided into 3 sections and can see 3 different images, using the 3 different sections. It doesn’t need 2 eyes to see in 3-D. One is enough. Besides that, it is able to judge depth much better than we are able to do it. Think of an image stitched out of 6 different eyes.

The Sweet Tale of the Mysterious Tree Lobster

By Anupum Pant

I do realize how big our world is and the sheer number of species that live in it. Also the fact that about 86% of the species are still unknown has me in awe all the time.

Yet, after having read about so many kinds of animals that live on our planet, after having documented them on this blog, I always feel that I’ve known and written it all. The very moment I start losing hope that I would never find an interesting animal ever again, something incredible comes across. Always!

Today, that happened again when I was reading an NPR blog. This time, there’s more than the species itself. The place where it lives is pretty awesome too. The most amazing part – This six-legged giant lives only there. That means, nowhere else on Earth will you find it! First, let’s see where it lives…

This is where it lives:

balls pyramid

I know, it looks like a CG mountain done for a fantasy movie. Trust me, it’s real. It’s called the Ball’s Pyramid (named after a European named Ball who first saw it in 1788) and was formed 7 million years ago due to a volcanic eruption. It is an awkwardly tall (1,844 feet) and an extremely narrow rock sitting in the centre of the sea. To the East of Australia, the red place marker in the following picture shows where the rock is located.

 balls pyramid location

 What lives there? And how was it found?

There is an island – Lord Howe island – close to the rock. In the island lived huge “tree lobsters” (actually they were huge stick insects with a hard exoskeleton – Dryococelus australis). In the year 1918, a ship crashed on the island and brought with it some rats. The rats loved these tree lobsters and finished them off within 2 years. After 1920, these tree lobsters were thought to be extinct.

tree lobster

Of course there were stories of these insects living on a rock near the island. But no human wanted to climb the narrow rock to hunt insects at night.

Only in the year 2001 when 2 researchers David Priddel and Nicholas Carlile decided to climb up the rock to find out if these stories were real, they found something incredible. Poop of a large insect. When the came back at night to investigate, the shiny black huge tree lobsters were found! These insects had probably never been extinct.

For more than 80 years, 24 of them had been living on this rock, in a bush and no one knew how they got there. Probably they clinged on to birds or something. Also, according to the researchers, these creatures have never been seen anywhere else.

Where are they now

I’m not sure about where they are now. According to the 2012 NPR article which I read, a pair of these creatures – Adam and Eve – were brought into Australia. Eggs got laid and little Tree lobsters came into the world. Thankfully, the species was saved from going extinct. But it isn’t known if they’ll be sent back to their home island because the great-great-great grandsons of those rats must still be there waiting to finish these insects off again.

This is how the first ones hatched in the zoo…

Hit like if you learnt something from this article.

Conan The Bacterium – The World’s Most Toughest Bacterium

By Anupum Pant

I have been a big fan of Tardigrades and the Radiotrophic fungi since the day I found out about them. I’m a fan mostly because these are the kind of creatures that can survive in very different (extreme) kind of settings. For instance, Tardigrades can waddle through the vacuüm of space without getting harmed! (more in the links above).

These are Extremophiles – creatures that can survive extreme heat, cold, dehydration, acidity, or radiation. But Extremophiles have their own abilities and specialties. That means, if they are able to survive one kind of harsh condition, say extreme heat, there is a fat chance that the same organism will have the ability to survive other harsh conditions too. That is not the case with the bacteria we see today…

The badass bacteria beats Tardigrades.

A bacteria that goes by the name Deinococcus Radiodurans enters. It is the king of Extremophiles. Or, you can call it a Polyextremophile (reason below). So, to my list of the most badass creatures, I’m happy to announce that I’m adding a new creature – Conan the Bacterium or Deinococcus Radiodurans (DR).
(If you don’t get it, it is a bacteria nicknamed after the badass barbarian warrior movie – Conan the Barbarian – not after the funny guy on TV – Conan.)

This bacterium is so tough that it is listed in the Guinness Book of World Records as “the world’s toughest bacterium”.

What can it survive? Now what makes it better than Tardigrades or any other known creatures out there, is its ability to withstand all of the extreme conditions at the same time – Polyextremophile. So, if you decide to put it through all of these conditions at the same time –

Vacuum + Zero humidity + 85 degrees C temperature + 500,000 rads of radiation

– it will survive. The most amazing part – it will survive all of it easily. To give you an idea how much 500,000 rads of radiation is, human beings would get cooked (or charred) to death within seconds if they get exposed to that amount of radiation! Yet Conan the bacterium takes it all as if it was nothing, and can still go up to 1,500,000 rads. At those levels, even the molecular structure of glass begins to break down!

Habitat: No one knows where this bacterium belongs naturally. It is found anywhere and everywhere. You might find it in elephant’s dung or in the polar areas of the earth where the environment of earth closely resemble that of Mars.

DNA repair with a twist: Like most other bacteria, DR can repair its own DNA after damage due to extreme amounts of radiation. But, even here, it manages to stand out from the masses (other bacteria). Other bacteria like E.Coli can’t survive, more than two or three major DNA breaks. However, DR can keep on bringing its broken DNA to the original state over and over. And every time, it can stitch back its completely blown DNA bits, in a matter of few hours. There is still a lot to learn about how it manages to do this.

However, the mechanism it uses is certainly different and better from the way other bacteria do it. It doesn’t seem to have any DNA repair genes like other bacteria. And yet it is able to make complete repairs in the DNA with the help of a certain protein.

Data storage: In the future, if we ever wish to make extremely robust storage devices, we could probably learn to store data in this bacteria’s DNA. And then we might never lose data even in the case of a nuclear apocalypse.

[Source 1] [Source 2] [Source 3]