A manta ray is a highly sensitive animal. The senses of manta rays help them navigate and interact with their environment. But those senses are not the same exact senses as most humans have and use every day… find a bit more about each of the manta ray’s “superhuman” senses in this article!
A Manta Ray’s Sight
Manta rays have well-developed eyes positioned on the sides of their head. This gives them an optimal field of vision, however, they do have two “blind spots”; one in front of them and the other one directly behind them.
Scientists are not sure how well manta rays can see; they seem to use their eyes to perceive shapes and navigate their surroundings both in clear water, but also when the ocean is murky or dark. It is apparent that they can see divers during the daylight hours as they often swim away from them when approached. At night, they will allow divers and snorkelers to be within a few feet of them while they are preoccupied with feeding.
Manta rays also have the ability to physically pull back their eyes into their sockets to protect them.
Sense of Touch
Similar to human skin, manta rays are sensitive to touch over their entire body.
They possess numerous tactile receptors known as dermal denticles, which are similar to tiny teeth, covering their bodies. These denticles allow them to sense touch and changes in water pressure.
Over the years, I have been hit or slapped around by mantas. Some parts of their body feel slimy, and other parts like fine sandpaper.
Their skin is also covered with a slime coating, which serves as a barrier to bacteria, aids in healing in the event of injury, and reduces friction as they swim through the water.
The Hearing of a Manta Ray
Manta rays possess an acute sense of hearing that allows them to detect sound waves in the water.
Unlike humans who rely on external ears for hearing, the inner ear of a manta ray is encased in its skull. Mantas have small holes called spiracles; these are located behind their eyes, and serve to channel water into their inner ear structures. This enables them to pick up vibrations from various sources.
The sacculus inside the inner ear has small hair-like nerve cells; when sound vibrations reach the sacculus, manta rays can tell which direction the sound is coming from.
How cool is that?
Most living organisms (from plankton to human beings) generate a weak bioelectric field by using their nerves and muscles.
Manta rays have specialized organs in their skin called “ampullae of Lorenzini”; these are small mucus-filled pores located around their head and on their underside.
Since water is a great conductor of electricity, these electroreceptive cells give mantas (and other types of fish) the ability to sense electrical fields that other living organisms emit.
Related fish (like sharks) will use electro-reception to locate prey; and it appears that manta rays use this particular sense to locate their main food source, plankton.
Can Manta Rays Smell? (Olfactory Sense)
Manta rays have two small, nearly invisible nostrils situated beneath their mouths. These are aligned with the water flow so water goes in one side and out the other.
Manta rays can’t stop swimming and are in constant forward motion. This creates a pressure difference that forces chemicals over the sensory folds.
Manta rays can detect even the faintest scent of their food source!
How about their Sense of Taste?
Manta rays have a distinct mouth structure that sets them apart from other marine creatures when it comes to tasting food. Their mouths are located at the front of their bodies, allowing them to efficiently filter-feed on plankton as they swim through the water with ease.
While mantas don’t have a tongue with taste buds, they can certainly taste their food…
Towards the back of their oral cavity, manta rays have very small protrusions, which can detect minute chemical concentrations. This gives them the ability to sense and consume their natural food source as well as to detect species-emitting chemicals from potential mates.
If something that they cannot digest or simply don’t want is caught in their mouth (like a fish, jellies, or plastic etc), they can reverse the pressure and spit it out. Read more about that in the post below!
Senses that Need More Research: Magneto Reception
Some theories pose that manta rays (and some other marine creatures) possess a sense of magnetoreception. This sense would allow them to detect the Earth’s magnetic field and use it for navigation during long-distance migrations.
This theory is still very hypothetical and will need a lot more investigating; read more here about research done on yellow stingrays (a close relative of the manta rays).
By combining all these different senses to navigate the ocean, mantas can
- Avoid obstacles such as rocks or coral reefs
- Effectively find food
- Interact with other marine life
All while swimming through complex underwater environments, from the shallow coastal waters where reef mantas roam – to the deep open oceans that host giant oceanic manta rays.