Latimeria: a description of the fish, where it lives, what it eats, interesting facts

The coelacanth fish, a representative of the underwater world, represents the closest link between fish and amphibious representatives of the fauna, which came out of the seas and oceans to earth about 400 million years ago in the Devonian period. Not so long ago, scientists believed that this species of fish was completely extinct, until in 1938 in South Africa, fishermen caught one of the representatives of this species. After that, scientists began to study the prehistoric coelacanth fish. Despite this, there are still many mysteries that experts are not able to solve to this day.

Fish coelacanth: description

It is believed that this species appeared within 350 million years ago and inhabited most of the globe. According to scientists, this species became extinct 80 million years ago, but one of the representatives was caught alive in the Indian Ocean in the last century.

Coelacanths, as the representatives of the ancient species are also called, were well known to specialists from the fossil record. The data indicated that this group developed massively and was very diverse about 300 million years ago during the Permian and Triassic periods. Experts working on the Comoro Islands, which are located between the African continent and the northern part of Madagascar, found that local fishermen managed to catch up to 2 individuals of this species. This became known quite by accident, since the fishermen did not advertise the capture of these individuals, since the meat of coelacanths is not suitable for human consumption.

After this species was discovered, over the following decades, it was possible to learn a lot of information about these fish, thanks to the use of various underwater techniques. It became known that these are lethargic, nocturnal creatures that rest during the daytime, hiding in their shelters in small groups, including up to a dozen or one and a half individuals. These fish prefer to be in water areas with a rocky, almost lifeless bottom, including rocky caves located at depths of up to 250 meters, and maybe more. Fish hunt at night, moving away from their shelters at a distance of up to 8 km, while returning back to their caves after the onset of daylight. Coelacanths are slow enough and only when danger suddenly approaches, they show the power of their caudal fin, quickly moving away or moving away from capture.

In the 90s of the last century, scientists conducted DNA analyzes of individual specimens, which made it possible to identify the Indonesian representatives of the underwater world as a separate species. After some time, the fish was caught off the coast of Kenya, as well as in Sodwana Bay, off the coast of South Africa.

Although much is still not known about these fish, tetrapods, colacants, and lungfish are the closest relatives. This was proved by scientists, despite the complex topology of their relationship at the level of biological species. You can learn about the remarkable and more detailed history of the discovery of these ancient representatives of the seas and oceans by reading the book: “Fish caught in time: the search for coelacanths.”

Appearance

This species has significant differences when compared with other types of fish. On the caudal fin, where other fish species have a depression, the coelacanth has an additional, not large petal. The bladed fins are paired, and the vertebral column remained in its infancy. Coelacanths are also distinguished by the fact that this is the only species with a functional intercranial joint. It is represented by an element of the cranium that separates the ear and brain from the eyes and nose. The intercranial junction is characterized as functional, allowing the lower jaw to be pushed down while raising the upper jaw, which allows coelacanths to feed without problems. The peculiarity of the body structure of the coelacanth is also that it has paired fins, the functions of which are similar to those of the bones of the human hand.

The coelacanth has 2 pairs of gills, while the gill lockers look like prickly plates, the fabric of which has a similar structure to the tissue of human teeth. The head has no additional protective elements, and the gill covers have an extension at the end. The lower jaw consists of 2 overlapping spongy plates. The teeth differ in a conical shape and are located on bone plates formed in the region of the sky.

The scales are large and close to the body, and its tissues also resemble the structure of a human tooth. The swim bladder is elongated and filled with fat. There is a spiral valve in the intestine. Interestingly, in adults, the size of the brain is only 1% of the total volume of the cranial space. The rest of the volume is filled with fat mass in the form of a gel. Even more interesting is that in young individuals this volume is 100% filled with the brain.

As a rule, the body of the coelacanth is painted in dark blue with a metallic sheen, while the head and body of the fish are covered with rare spots of white or pale blue. Each specimen is distinguished by its unique pattern, so the fish are noticeably different from one another and they are easy to count. Dead fish lose their natural color and become dark brown or almost black. Among coelacanths, sexual dimorphism is pronounced, which consists in the size of individuals: females are much larger than males.

Lifestyle, behavior

During the day, coelacanths are in shelter, forming a few groups of a little more than a dozen individuals. They prefer to be at depth, as close to the bottom as possible. They lead a nocturnal lifestyle. Being at depth, this species has learned to save energy, and encounters with predators are quite rare here. With the onset of darkness, individuals leave their hiding places and go in search of food. At the same time, their actions are rather slow, and they are located at a distance of no more than 3 meters from the bottom. In search of food, coelacanths swim considerable distances until the day comes again.

Interesting to know! Moving in the water column, the coelacanth carries out a minimum of movement with its body, trying to save as much energy as possible. At the same time, she can use the underwater currents, including the work of the fins, only to regulate the position of her body.

The coelacanth is distinguished by the unique structure of its fins, thanks to which it is able to hang in the water column, being in any position, either upside down or up. According to some experts, coelacanth can even walk along the bottom, but this is not at all the case. Even being in a shelter (in a cave), the fish does not touch the bottom with its fins. If the coelacanth is in danger, then the fish is able to make a swift leap forward, due to the movement of the caudal fin, which is quite powerful in it.

How long does coelacanth live

It is believed that coelacanths are real centenarians and are able to live up to 80 years, although these data are not confirmed by anything. Many experts are sure that this is facilitated by the measured life of fish at depth, while the fish are able to economically expend their strength, escape from predators, being in optimal temperature conditions.

Types of coelacanth

Coelacanth is the name used to identify two species such as Indonesian coelacanth and Coelacanth coelacanth. They are the only living species that have survived to this day. It is believed that they are living representatives of a large family, consisting of 120 species, which are attested in the pages of some chronicles.

Range, habitats

This species is also known as the “living fossil” and it lives in the western waters of the Pacific Ocean, bordering the Indian Ocean, within the Greater Comoro and the Anjouan Islands, as well as within the South African coast, Mozambique and Madagascar.

It took several decades to study the populations of the species. After the capture of one specimen in 1938, it was considered for the whole sixty years the only specimen representing this species.

Interesting fact! At one time there was an African program-project “Celacanth”. In 2003, IMS decided to join forces with this project to organize further searches for representatives of this ancient species. Soon, the efforts paid off and already on September 6, 2003, another specimen was caught in the south of Tanzania in Songo Mnare. After that, Tanzania became the sixth country in the waters of which coelacanths were found.

In 2007, on July 14, fishermen from northern Zanzibar caught several more individuals. Specialists from IMS, the Institute of Marine Sciences of Zanzibar, immediately went with Dr. Nariman Jiddawi to the scene, where they identified the fish as “Latimeria chalumnae”.

The diet of coelacanths

As a result of observations, it was found that the fish attacks its potential prey if it is within reach. To do this, she uses her rather powerful jaws. The content of the stomach of the caught individuals was also analyzed. As a result, it was found that the fish also feed on living organisms that it finds in the soil at the bottom of the sea or ocean. As a result of observations, it was also established that the rostral organ has an electroreceptive function. Thanks to this, the fish distinguishes objects in the water column by the presence of an electric field in them.

Reproduction and offspring

Due to the fact that the fish are at great depths, little is known about it, but something completely different is clear – coelacanths are viviparous fish. More recently, it was believed that they lay eggs, like many other fish, but already fertilized by the male. When females were caught, they found caviar, the size of which was the size of a tennis ball.

Interesting information! One female is able to reproduce, depending on age, from 8 to 26 live fry, the size of which is about 37 cm. When they are born, they already have teeth, fins and scales.

After birth, each baby has a large but sluggish yolk sac around the neck, which served as a source of food for them during the gestation period. During development, as the yolk sac becomes depleted, it is likely to shrink and become enclosed in the body cavity.

The female bears her offspring for 13 months. In this regard, it can be assumed that females can become pregnant no earlier than the second or third year after the next pregnancy.

Natural enemies of coelacanth

Sharks are considered the most common enemies of coelacanth.

Fishing value

Unfortunately, coelacanth fish is of no commercial value, since its meat cannot be eaten. Despite this, fish are caught in large numbers, which causes serious damage to its population. It is mainly caught in order to attract tourists, creating unique stuffed animals for private collections. At the moment, this fish is listed in the Red Book and banned from trading on the world market in any form.

In turn, the local fishermen of the island of Great Comoro voluntarily refused to continue to catch coelacanths that live in coastal waters. This will save the unique fauna of coastal waters. As a rule, they fish in areas of the water area that are unsuitable for the life of the coelacanth, and in case of capture, they return individuals to their places of permanent natural habitat. Therefore, an encouraging trend has recently emerged, as the population of the Comoros monitors the conservation of the population of this unique fish. The fact is that coelacanth is of great value to science. Thanks to the presence of this fish, scientists are trying to restore the picture of the world that existed several hundred million years ago, although this is not so simple. Therefore, coelacanths today represent the most valuable species for science.

Population and species status

Oddly enough, although the fish is of no value as an object of subsistence, it is on the verge of extinction and therefore is listed in the Red Book. The coelacanth is listed on the IUCN Red List as Critically Endangered. In accordance with the international treaty CITES, coelacanth has been assigned the status of a species that is endangered.

As mentioned above, the species has not yet been fully studied, and today there is no complete picture for determining the coelacanth population. This is also due to the fact that this species prefers to live at considerable depths and is in shelter during the daytime, and it is not so easy to study anything in complete darkness. According to experts, back in the 90s of the last century, a sharp decrease in the number within the Comoros could be observed. The sharp decrease in numbers was due to the fact that coelacanth often fell into the nets of fishermen who were engaged in deep fishing of completely different species of fish. This is especially true when females that are at the stage of bearing offspring come across in the net.

In conclusion

We can safely say that coelacanth is a unique species of fish that appeared on the planet about 300 million years ago. At the same time, the species managed to survive to this day, but it will not be so easy for her (coelacanth) to survive some 100 years. Recently, a person has little thought about how to save one or another type of fish. It is hard to even imagine that coelacanth, which is not eaten, suffers from rash human actions. The task of mankind is to stop and finally think about the consequences, otherwise they can be very deplorable. After the objects of subsistence disappear, humanity will also disappear. There will be no need for any nuclear warheads or other natural disasters.