Rays are truly amazing animals. Watching one glide through water is a remarkable sight. Unlike other aquatic animals, they almost seem to fly through the water. They also look like no other animal on earth.
Ray Appearances
Rays are basically flattened fish. They have a mound in the middle that juts out a bit, but otherwise all rays are just large flat discs. These discs differ in size and shape from ray to ray. Most are circular, wedge-shaped, or triangular.
Rays also have tails. The tails differ in size for each ray species, and they differ in function too. In some rays, the tail is used as a stinger. These rays, called stingrays, use their tail to stun their prey. These rays then eat the animals that they sting.
Other rays use their tails for self-defense. Some rays’ tails poison any predator that attacks them. Other rays have spikes in their tail. This type of ray will whip its tail at predators to scare them away.
For many other rays, the tail is able to detect dangerous predators. The manta ray, for instance uses the tail to protect its blind spot. Manta rays’ tails function as a type of security system, then.
Really, though, most animals do not attack rays. Their shape makes them hard to eat. And most rays move much faster than other aquatic species can.
Rays and Sharks
Rays look practically nothing like sharks. But scientists actually say rays and sharks are very similar. Both are completely made of cartilage, for instance. Cartilage is a tough material, but it is softer than bone. Most aquatic species have bones, but rays and sharks do not. Rays and sharks also have both similar teeth and spine structures.
Rays may be very similar to sharks, but many behave more like fish. Unlike sharks, most species of rays are social. They live and hunt in groups. Rays also are unlike sharks in how they eat.
Most rays are bottom-feeders. Their mouths are on their bottom sides, and their eyes are above. These rays use their eyes to see what’s ahead of them, while their mouths scrape the ocean floor for food. Other rays swim constantly and have mouths that open on their front side. These rays sweep food into their mouths as they swim.
Sharks, on the other hand, hunt in a more active way. They seek out prey and chase it down. Some sharks actually follow rays. When rays swim into an area, fish will often hide. When the rays leave, the fish return. When they return, a shark emerges from hiding to eat the fish.
Rays and sharks are both very smart animals. Rays have large brains for their body weight. The higher an animal’s brain to body ratio, the smarter it is. By that measure, marine biologists say that it is likely that rays are even smarter than most sharks.
Rays show their intelligence in different ways. They are smart enough to avoid fights with other animals. And they also show an interest in their environment that most fish do not. Many divers have reported rays coming up to them and just watching them. The divers describe the rays as seeming to observe them, just as marine biologists might observe and monitor rays. Of course, no one knows for sure what the rays are thinking when they see humans diving into their habitats. But they are clearly curious. And curiosity is a sign of intelligence in the animal world.
Ray Types
As mentioned earlier, not all rays are the same. In fact, there are about 500 different types of rays in the world. These include eagle rays, which have distinct spots, cownose rays, which have flat noses, and southern rays, which are large and round.
The largest ray is the manta ray. It can be up to 22 feet wide and weigh several tons. The smallest rays are the electric rays. They are only about as big as a piece of bread and weigh around a pound. Most rays are larger than two feet in width but not as big as the manta ray.
Rays live all over the world in almost every ocean environment imaginable. Some live close to the surface. Others live over 10,000 feet below the surface. A few ray species can also jump above the water.
All rays move in the same fashion. They glide through the water at times and use their fins like wings at other times. That is, they move them up and down like a bird might.
Ray Importance
Rays play a huge role in the marine world. First, like most fish species, they are part of the food chain. They eat mollusks and other shellfish off the ocean floor. Some species also eat plankton, and others filter small fish into their mouths. By eating all these things, rays keep the populations of the species in balance.
More important, rays help unearth food for other species. Rays move sand when they swim on the ocean’s floor to find their own food. When they move the sand, other things are dug out. According to marine biologists at Murdoch University, other species can become aware of food they did not know about because of this process. And, as mentioned above, rays often help sharks find food.
Because of this, rays are like all other animals in the world in one way. They are important to the balance of nature. Without rays, the ocean world would be changed. And those changes could be for the worse. Like all species, rays should be protected. Luckily, rays are pretty good at defending themselves!