Shipworms: class, photo, habitat
Evolution changes many beyond recognition, but the worms, mollusks and other invertebrates over millions of years remain unchanged. Many, but not all. Shipworms are one of the most amazing creatures of nature that have managed to adapt to almost all habitats, where they were brought by chance. You are interested? Then let's find out together who these unusual shipworms are.
Teredo: short description
Shipworms, or treedos, as they are called, resemble whitish-colored long worms, reaching in some cases up to one meter in length. An adult individual prefers to spend all his life in wood, which is in salty sea water. The waters of tropical and temperate latitudes are considered ideal for them; in the cold seas, the queue does not survive. Nor can they exist in water, where the salt concentration falls below ten percent.
At the moment, scientists know more than seventy kinds of shipworms, some of them are even bred by the peoples of Oceania for eating, considering them to be a delicacy.
If you show this creation of nature to an ordinary person, he will surely say that he sees a worm in front of him. But it is not. In fact, before you clam. In the course of evolution, the shipworm has managed to change almost completely and adapt to the conditions of dwelling in narrow and long passages. After all, they save the creature from the enemies and serve as a source of food.
You may find this incredible, but the shipworm belongs to the class of bivalve mollusks. He has a shell, which during evolution has turned into a small tip in front of the body.
Small queues are more similar to mollusks familiar to us, but literally in the first couple of weeks of life they break through their first move and already represent a smaller copy of the adult.
Habitat of shipworms
As we have already mentioned, in turn, in large quantities live in the southern seas.Most of them are in mangrove forests. The roots of these trees are always in the water, and the trunks that have fallen into the sea become a dwelling place for the trunk. But shipworms can dig passages in any wood that gets into the water. Quite often they became the cause of the death of ships, and the sailors tried by all means to get rid of the pests that millions of people settled on the bottom of the ship. Literally in six months, a colony of shipworms is capable of destroying a whole fleet consisting of wooden ships.
Also love the Treedo and piles, on which stood the pier of port cities. For them, shipworms were a real disaster. For example, in Sevastopol piles could serve no more than two years. During this time, the turn turned them into a kind of sieve from numerous moves.
Black Sea: how to get to us
The shipworm in the Black Sea feels very confident. About fifty years ago, he was the scourge of local residents and caused irreparable harm to human economic activity. But how did this mollusk get into our waters?
Biologists believe that shipworms were brought into the waters of the Black Sea from the Persian Gulf.It is here that the nearest mangrove forests are located, moreover, in the waters of the Gulf, the concentration of the treedo reaches a critical level of fifty individuals per square centimeter. It is therefore not surprising that the merchant ships were infested with them.
Three species of described mollusks inhabit the waters of the Black Sea. Usually they do not reach a length of more than twenty-five to thirty centimeters. But there are isolated cases when the Black Sea shipworms, the photos of which we cited in the article, were sixty five centimeters long.
Shipworms have a long cylindrical body. The length of an adult individual ranges from twenty-five centimeters to two meters. The clam spends its whole life in a hole dug by it. Almost at the stage of the larva, he begins to dig his turn in a piece of wood and continues to do so as it grows, therefore the hole in the hole is usually no more than five millimeters in size. In the future, the course expands and can be up to five centimeters in diameter, depending on the size of the individual.
Shipworms at the front end of the body have a small double shell, the flaps of which consist of three parts. The ear and the body of each flap are equipped with sharp notches, it is they who help to dig tunnels.Getting into the course, the mollusk is fastened inside with the help of a leg in the front part of the body and with the progressive movements it begins to create a tunnel deep into the piece of wood. Surprisingly, the moves of the shipworms never intersect. Biologists believe that the sound that is made when scraping wood is heard by all their neighbors and carefully bypass the already occupied territory.
As you move through the tunnel, the clam covers its walls with a layer of limestone. Virtually the entire body of the turn is inside the course, only siphons remain outside - a pair of long processes that perform the function of the respiratory organs through which sea water is filtered and the mollusk is fed. In case of danger, shipworms siphons into the course and close the hole with a small plate located at the end of the body.
How a shipworm feeds
Shellfish feed on organic matter, which is filtered from seawater. But shipworms also feed on sawdust left over from digging. The stomach of the stomach with the help of bacteria located on the gills produces cellulose-splitting enzymes.Therefore, it is almost completely clogged with sawdust.
Interesting facts about shipworms
Now it’s hard to imagine how hard the hard-working mollusks can do. After all, people have learned to cover a tree with a special poisonous compound that scares them, and piles are often made of concrete. But once the turn almost killed the whole country.
In the first half of the eighteenth century, almost half of Holland was threatened with flooding. The fact is that on the coast in the large number of lottotstsev bred and began to literally destroy the piles of dams that protect the country from the sea. The Dutch had several years tirelessly to change the piles to new ones in order to eliminate the threat of flooding of the surrounding provinces.
Do you think this is too ancient a fact? Then we can bring something more fresh. At the beginning of the twentieth century, San Francisco lost almost all of its piers — they were eaten by a turn. The mollusk, which began to actively proliferate, flooded the entire coast, which led to disastrous consequences for the port city.
If this article gives you the impression that the queues are real pests and do not bring any benefit, then you are mistaken. They occupy an important place in the marine ecosystem.After all, wood, transformed into molten dust by the actions of mollusks, is a source of food for other marine creatures.