The Smartest Fish in The Sea Manta rays are not only a pleasure to observe, they’re also extremely intelligent and have large brains. Researchers study what’s known as the ‘brain to body mass ratio’ as part of classifying the capabilities of different animals. Manta rays have a high ratio, so high in fact that they are in the same range as mammals – with the highest brain to body mass ratio of any fish in the ocean.Despite being a cold-blooded animal, they have an ability called a ‘counter current heat exchange mechanism’ which allows certain areas of their brains to be warmed, leading to more activity in those areas. Certain brain areas we usually associate with humans for complex problem solving, social structure and memory are also highly developed – all good indicators of their intelligence.Despite this knowledge, there is still much to learn about these fascinating creatures. One of the ways that researchers have attempted to study them unobtrusively is by tracking different mantas based on individual markings. Every manta ray has a unique spot pattern on its belly almost like a fingerprint – which helps researchers to identify, track and study individuals..They travel vast distances, often in a short space of time, and have been tracked descending to depths of over 1,340 m (4,440 ft). Researchers still do not know why mantas dives so deeply, leaving room for future study.