Electric ray

Electric rays are flat fish. They have soft skin. They do not have thorns.

These fish have two special parts. These parts make a spark. They use the spark to stun food. This helps them eat.

They also use it to stay safe. They hide in the sand.

Some rays live in salt water. Others live in fresh water.

They move with their tails. They are very slow swimmers.

It is a very amazing fish!

Electric rays are flat fish. They have soft skin. They do not have thorns.

These fish have two special parts. We call these electric organs. They are shaped like kidneys. They sit near the head. These parts make a spark. This spark is a discharge of power. It can be 8 volts or 220 volts.

The rays use this power to stun prey. They hide under the sand. They wait for small fish. When a fish swims by, the ray uses its spark. This helps the ray catch food. They also use it to stay safe from danger.

Most rays swim with their side fins. Electric rays are different. They are slow swimmers. They use their tails to move.

Some rays live in salt water. Others live in fresh water. Fresh water rays have a special way to use their organs. They link them in a series. This helps them send out more power. This is helpful because fresh water does not carry electricity as well as salt water.

Electric rays are a special group of flat fish. They belong to an order called Torpediniformes. These fish are made of cartilage instead of bone. They have thick, soft bodies and loose skin. You will not find any thorns or sharp scales on them. Most rays use their side fins to swim through the water. Electric rays are different because they move slowly. They use their strong tails to push themselves along.

These fish have two large electric organs near their heads. These organs are shaped like kidneys. They are made of many tiny parts called plaques. Each plaque comes from special muscle. These plaques are stacked in columns like a honeycomb. A nerve tells the organ when to release its power. The electricity flows from the bottom to the top of the fish. This creates a discharge to stun prey or stay safe.

People have known about these fish for a very long time. The ancient Greeks used them to numb pain during medical work. A Roman doctor named Scribonius Largus wrote about them in 46 AD. He said they could help with headaches. In the 1770s, scientists like John Walsh and John Hunter studied them. Henry Cavendish even built a fake ray in 1773. He used jars to mimic how the fish works.

There are 69 different species in four main families. One family is called Torpedinidae, or torpedo rays. Another group is the Narcinidae, which are electric rays. The voltage they make can change a lot. Some species only make 8 volts. The Atlantic torpedo, called Torpedo nobiliana, can reach 220 volts. Freshwater rays are special too. They link their organs in a series to send more power. This helps because fresh water does not carry electricity as well as salt water.

These rays are great hunters that like to hide. They lie still under the sand or on the bottom. They wait for small fish or invertebrates to swim by. When food gets close, the ray uses its spark to stun it. This makes it easy to swallow the prey whole. The name "torpedo" actually comes from the Latin word for being paralyzed. This is how the fish makes its prey feel.

Electric rays are a specialized group of cartilaginous fish. They belong to the biological order Torpediniformes. These animals are defined by their ability to produce an electric discharge. They use this electricity to stun prey and for defense. There are 69 known species divided into four main families. These fish have flat, thick, and flabby bodies. Their skin is soft and loose. Unlike many other rays, they lack dermal denticles or thorns.

The biological mechanism of their power comes from specialized electric organs. These organs are shaped like kidneys and sit at the base of the pectoral fins. Each organ is composed of many hexagonal columns arranged in a honeycomb formation. These columns contain between 500 and over 1,000 tiny plaques. These plaques are actually modified striated muscle cells. They are adapted from the branchial muscles, which are the muscles of the gill arches. Nerves signal the organ to discharge by branching out to these plaques. When the signal arrives, the current passes from the lower surface to the upper surface of the fish.

How these batteries are connected depends on the water environment. In marine fish, the electric organs are connected as a parallel circuit. However, freshwater rays arrange their batteries in a series circuit. This structural difference is very important for their survival. Freshwater does not conduct electricity as well as saltwater. By using a series arrangement, freshwater rays can transmit a much higher voltage. This allows them to remain effective hunters even in less conductive water.

There are different types of electric rays with different hunting styles. The family Torpedinidae, or torpedo rays, typically feeds on large prey. They use their electricity to stun these animals and then swallow them whole. In contrast, the Narcinidae family specializes in much smaller prey. These rays often hunt animals that live in or on the bottom substrate. While both families use electricity for defense, it is not yet clear if Narcinids use it for feeding. Other families in the order include the Platyrhinidae, known as thornbacks, and the Hypnidae, called coffin rays.

Humans have been fascinated by these fish since ancient times. The Greeks used electric rays to numb pain during operations and childbirth. In 46 AD, the Roman physician Scribonius Largus recorded using them to treat gout and headaches. Even the philosopher Plato mentioned the fish in his dialogue, Meno. He used the fish as a metaphor for how Socrates could stun people with questions. In 1773, Henry Cavendish even built an artificial ray. He used fish-shaped Leyden jars to mimic the electric behavior of the real animal.

The study of these rays helped create modern science. In the 1770s, researchers John Walsh and John Hunter published papers on the electric organs. Their work influenced Luigi Galvani and Alessandro Volta. These two men are considered the founders of electrophysiology and electrochemistry. The voltage produced by these rays varies significantly by species. Some narcinids produce only 8 volts. However, the Atlantic torpedo, Torpedo nobiliana, can reach a powerful 220 volts.

In many cultures, these rays were seen as magical or occult. Before people understood electricity, the fish seemed to have supernatural powers. Fishermen were often numbed by the rays without even being touched. This led to many legends in premodern natural histories. Today, we understand that this is a biological process rather than magic. These rays remain vital members of their ecosystems, from shallow coasts to deep waters. They move slowly by using their muscular tails rather than their fins.