December 22, 2020 - A giant ray smiles brightly while being fed in Kanagawa, Japan.

Divers enter the aquarium to see if there are any dead fish, but the rays think this is a good time to find food.

When the diver had eaten all the food, Ray was still reluctant to let the diver go.

Rays, cartilaginous fishes, skates.

The rays are found in all temperate and tropical shallow waters except the South Pacific and the northeastern coast of South America.

Rays are harmless bottom-dwelling animals that are usually partially buried in the sand.

They vary in size.

The adult body of a small ray is only 50 centimeters, while the adult body of a large ray is 8 meters long.

It has a flat, diamond-shaped body, and the fish's entire pectoral fins look like a pair of large wings.

The skate is a cartilaginous fish.

It has a flat, rhombus-shaped body with a strange and elegant shape.

The fish's entire pectoral fins look like a pair of large wings.

Like flying while swimming.

They have protruding round eyes and two slits on their heads, through which oxygen-rich seawater enters the body and is discharged through the gill slits on the abdomen behind the mouth.

The endoskeleton of the ray is completely composed of cartilage. After calcification, some parts have a certain hardness, but it is different from the ossified bone tissue.

Body surface scales are composed of ectoderm and mesoderm; scales and teeth are homologous.

The mouth is not located on the beak, but on the abdomen and transverse slit; the even fins are horizontal; the caudal fin is curved.

The stomach is well differentiated, with an independent pancreas and a well-developed liver.

There are spiral valves in the intestine.

There is no swim bladder.

The gill gap is very long, extends to the body surface, and is connected to the skin, so the gill slits open directly on the body surface.

The heart has a cone of arteries.

The male reproductive tract borrows from the mesonephric duct.

A single cloacal orifice is opened externally.

Males have a mating organ called a flipper.

Oogenesis, viviparous or pseudoviviparous, internal fertilization, in vitro development or internal development.

The number of eggs laid is small, but the survival rate is high.

The brain is developed, even taller than that of bony fish.

The brain is huge and there is a lot of neural material at the top of the brain.

The ray is round or diamond-shaped, with wider pectoral fins that extend from the tip of its snout to the base of its slender tail.

Some species have pointed noses, flat bodies, and elongated tails.

Some species have one or more serrated stingers on their tails.

The ray has eyes and blowholes at the top of its head and at the bottom of its snout, formed by coral-like cartilage protruding from the skull.

Most species have spines or spines on their backbones, and some have electricity-generating organs in their tails.

They are rectangular in shape and protected by a leather casing.

Skates come in different sizes. Small skates for adults are only 50 centimeters long; adults with large skates are 2.5 meters long.

Rays are harmless bottom dwellers that are usually partially buried in the sand.

Swim with your pectoral fins, making a nice wave-like forward swing.

They feed on molluscs, crustaceans and fish, swooping down from above to capture their prey.

The ray's eyes and spiracles are on the top of the head, and the snout is on the underside.

These are the gradual evolution of light to adapt to life under the sea.