Holiday Ayo - When talking about smart animals, fish probably rarely come to mind. In the world of fish, the title of the smartest fish deserves to be given to the manta ray. 

Manta rays have large brains, the largest of all fish. Their brains develop in areas for learning, problem solving, and communicating. 

Manta rays love to play, are curious, and can even recognize themselves in the mirror, which is a sign of self-awareness. 

The brain of a manta ray can be ten times larger than that of a whale shark. The brain is not only physically large, but also large compared to the stingray's body. 

This is another sign of super intelligence that also applies to elephants, dolphins and humans, as quoted from Oceana. 

A 2016 study found manta rays do not try to interact with their mirror image and exhibit unusual and repetitive movements in front of a mirror.

This indicates a contingency check, which is when an animal moves to test whether its image is moving.

These behaviors include rolling and unrolling the fins with its mouth and blowing bubbles while looking in a mirror.

However, the researchers note that marker tests are still needed to determine whether this is a form of self-awareness.

Manta rays may have the largest brains of any fish in the ocean, but others say we can't assume that's directly correlated with intelligence. 

Researching animal intelligence raises a complicated problem, namely how to measure it? 

“I think many researchers understand that intelligence is a concept that is difficult to define and even more difficult to test fairly," Dr Alecia Carter of University College London, an expert in animal behaviour, told IFLScience. 

“However, animals have some pretty impressive intelligence that is completely inaccessible to us," he said.