Mantis shrimp is a tiny marine crustaceans of the order Stomatopoda. Despite being small in size and having equally tiny brain, it has the most complex visual system of any living animal. In fact, a mantis shrimp four times as many colour receptors as humans do.
A new study from the University of Queensland attempted to figure out how tiny brain of mantis shrimp deal with that kind of volume of visual input.
While humans have three colour (red, green, and blue) receptors, mantis shrimp have 12. They have much more visual information than we do. They see things we cannot see. And the things that we do see, they see completely differently. This is a blessing and a curse, because this kind of a volume of visual input gives mantis shrimp quite a bit of an advantage, but is difficult to process. And yet they somehow manage without their brains exploding.
A mantis shrimp has two protruding eyes. They are hilariously large and work as high-definition cameras. Scientists researched the brain of this little animal and found that the secret to managing such a huge amount of visual information lies within the reniform body. It is a region of the brain found in each of the eye stalks. Dr Hanne Thoen, one of the authors of the study, said: “Using a variety of imaging techniques, we traced connections made by neurons in the reniform body and discovered that it contains a number of distinct, interacting subsections”.
Mantis shrimp have very complex retinas that feed into a very complex nerve centre, constructed from many different subsections. Scientists think that those subsections are most likely dealing with different types of colour information. This data is then sorted by its content and packaged for the brain to make any sense from it. If this system works this way, it is a very efficient way to process an unbelievably huge amount of information very quickly. In fact, there is a neural connection between the reniform body and a brain region known to be involved with memory, which means that mantis shrimp may also be collecting visual memory.
This is a good example, showing that even the most simple of animals can have abilities that rely on complex biological systems. Mantis shrimp may be a very simple animal, but there is nothing simple about the way it sees and processes the visual information. Unlike most crustaceans, mantis shrimp sometimes hunt, chase, and kill prey, which requires a good vision. They also need to recognize and hide from predators and defend their territory.
Scientists will continue their work. They want to know how all the subunits of the reniform body work together to allow mantis shrimp to interpret the world it sees.
Source: University of Queensland