Black swallower

The black swallower is a small fish.

It lives in the deep, dark sea. This fish is a brownish-black color. It has a very large mouth. It can eat fish that are much bigger than itself.

Its stomach can stretch very far. This helps it swallow prey. Some fish it eats are twice its length. It even eats prey that are ten times its weight. This fish is a wonder of the deep ocean.

The black swallower is a small fish from the deep sea.

It lives in warm ocean waters. Most of these fish are brownish-black. They have long bodies and no scales.

This fish has a very large mouth. Its teeth are special. They are called canines. These are large, sharp teeth. The teeth are mobile. This means they are loose in their sockets. This helps the fish chew its food.

The black swallower can eat very big prey. It eats bony fish and cephalopods. Cephalopods are animals like squid. The fish can swallow prey twice its length. It can also eat prey ten times its mass. Its stomach is distensible. This means the stomach can stretch a lot.

One fish ate a snake mackerel. That meal was four and a half times its own length! Sometimes, the food is too big to digest. The food starts to rot inside. This makes gases. The gas can push the fish to the surface.

These fish lay eggs in the ocean. The eggs have small oil drops inside. The tiny babies start out with dark spots. Soon, their whole body turns black.

The black swallower is a very special fish from the deep sea.

It lives in warm waters across the world. These fish stay in the mesopelagic and bathypelagic zones. These are deep parts of the ocean. This fish is quite common in the North Atlantic. It is the most common species in its group there. It is a small fish that stays brownish-black.

This fish has a very interesting way of eating. It can swallow prey much bigger than itself. It eats bony fish and cephalopods, which are animals like squid. Its stomach is distensible, meaning it can stretch a lot. A fish can swallow something twice its length. It can even eat prey ten times its mass. The jaws can swing down to grab big objects.

How does it swallow such huge meals? One idea is that it grabs prey by the tail. Then, it might "walk" its jaws over the prey. This helps coil the food inside the stomach. The teeth help with this hard job too. The fish has large teeth called canines. These teeth are mobile, so they are loose in their sockets. This helps the fish chew its food.

Scientists have found many amazing things about this fish. In 2007, a dead black swallower was found near Grand Cayman. This fish was 15 centimeters long. It had swallowed a snake mackerel in its stomach. That mackerel was 67 centimeters long. That is four and a half times the fish's length! Sometimes, the food is too big to digest. The food rots and makes gas. This gas can float the fish to the surface.

Life begins with tiny eggs in the ocean. These eggs are pelagic, meaning they float in the water. The eggs have a clear oil globule inside. They also have six dark pigment patches. These patches move along the body of the tiny larva. Soon, the dark spots disappear. The whole body then turns black. Many eggs are found near South Africa in winter. Young fish have been seen near Bermuda from April to August.

The black swallower, known scientifically as Chiasmodon niger, is a unique deep-sea fish.

It belongs to the family Chiasmodontidae. This species is famous for its ability to consume prey much larger than its own body. These fish live in tropical and subtropical waters around the globe. They inhabit the mesopelagic and bathypelagic zones of the ocean. These are very deep layers of the sea. The black swallower is a very common and widespread species. In the North Atlantic, it is the most common member of its genus.

Physically, the black swallower is a relatively small fish. It averages about 10 centimeters in length. The maximum length recorded for this species is 25 centimeters. Its body is elongated and compressed. It does not have scales and is a uniform brownish-black color.

The head is long with a blunt snout and moderately sized eyes. A large mouth is a key feature of its anatomy. The lower jaw actually protrudes past the upper jaw. Both jaws are lined with a single row of sharp, depressible teeth. These teeth interlock when the mouth is closed to secure prey. The first three teeth in each jaw are enlarged into canines.

Its dentition, or tooth structure, is quite specialized for its diet. The black swallower possesses fangs that are incurred and almost fully straight. These fangs are mobile, meaning they are loose in their sockets. This mobility helps the fish damage and chew its prey. Usually, the fish has multiple fangs. The second fang in the set tends to be the largest. This specialized mouth allows the fish to tackle difficult meals. The fish also has specific fin structures. It has long pectoral fins with 12 to 14 rays. The pelvic fins are small and contain five rays. It possesses two dorsal fins, where the first is spiny and the second is longer with soft rays.

Feeding is the most remarkable aspect of the black swallower's biology. It feeds on bony fish and cephalopods, such as squid, by swallowing them whole.

The fish has a greatly distensible stomach. This means the stomach can stretch significantly to accommodate large volumes. It can swallow prey that is over twice its own length. It can even consume prey that is 10 times its own mass. The upper jaws are articulated with the skull at the front via the suspensorium. This anatomical connection allows the jaws to swing down. This movement enables the fish to encompass objects much larger than its own head.

There are theories about how the fish manages such massive meals. Theodore Gill speculated on a specific method of ingestion. He suggested the swallower seizes prey fish by the tail first. It then "walks" its jaws over the prey. This process continues until the prey is fully coiled inside the stomach. Sometimes, the prey is so large that the fish cannot digest it quickly enough. Before digestion is complete, decomposition begins to occur. This decomposition releases gases inside the fish. The resulting gas buildup can force the swallower to float to the ocean surface. This is how most known specimens have been collected by researchers.

One notable example of this extreme feeding occurred in 2007. A dead black swallower was found off the coast of Grand Cayman.

This specific specimen measured 15 centimeters in length. Inside its stomach, scientists found a snake mackerel. The snake mackerel was 67 centimeters long. This means the prey was four and a half times the length of the swallower. This event highlights the incredible capacity of the fish's distensible stomach and its role in the deep-sea food web.

Reproduction in the black swallower is an oviparous process. This means the fish lays eggs that hatch outside the body. The eggs are pelagic, which means they float in the open water. Each egg measures about 1 millimeter in diameter. Inside the egg, there is a clear oil globule and six dark pigment patches. As the larva grows, these patches are distributed from the area in front of the eyes to the tip of the notochord. Eventually, these pigment patches disappear. The body of the fish then darkens overall to a black color. Most eggs are found during the winter off the coast of South Africa. Juveniles have been observed near Bermuda between the months of April and August. These young fish are covered in small, projecting spinules.