Friday 20 February 2015

Finding Dory in Mexico

A marine paradise underneath Mexico City: Inbursa Aquarium.

I enjoyed visiting this place so much. Four underground levels where you can see over 15,000 varieties from 300 species! Not easy when Mexico City is quite far from the sea.

I saw sharks, manta rays, penguins, and other fish I had never seen before. However, my younger self wanted to find Dory. I was not the only one though. All these kids were also wondering where Dory was. After looking through many fish tanks, we finally spotted her!




I did not have a clue what kind of fish Dory was. Something I learned from my visit was that Dory (Paracanthurus hepatus) is a surgeonfish. They have other names like the regal tang or blue tang.

One thing I love about Dory is her colours. What makes Dory have such a beautiful blue body with a black stripe and a yellow tail?

Dory’s blue colour is due to the reflection of blue wavelengths from the surface of her body. If you zoom in on the surface, you will find cells called iridophores, which in turn contain tiny crystals that reflect the light. These crystals are called reflective platelets.

Apart from blue, Dory has a yellow tail and a black stripe. The colour in these cases is not due to reflective platelets but to the presence of cells that make pigments: Xanthophores make the yellow and melanophores make the black.




Colours in animals help them to adapt to their environment. For example, they can change colour to match the background and hide from predators, or they can display their colours to attract a partner. So how can animals change their colours?


Colour changing is known as physiological colour change. It happens when the pigments inside the cells move. For example, the melanophores contain the black pigment called melanin. If melanin is properly distributed within the cells, the skin colour is black, but when melanin aggregates the skin turns paler. In the case of iridophores, which don’t have any pigments, the reflective platelets change their angles to reflect the light in another way.

Wow, isn't Dory amazing?


Oh! And don't forget to visit the aquarium if you go to Mexico City.You’ll love it!


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