Some crustaceans we perceive as a delicacy food-for example crayfish, crabs, shrimp, lobster, lobster and others. Scientists know more than 70 thousand arthropods - from huge "sea spiders" to tiny shrimp. These animals firmly occupy their place in the ecosystem of the planet, there are many interesting facts about them.
Freshwater
Interesting facts about Crayfish living in rivers and fresh lakes. Woodlice are like insects, but they are actually crustaceans. They do not live in water, but for life choose damp darkened places. They feed on plant residues.
Have cancers and lobsters under loss of claws grows up a new. Although the new ending may be smaller and not very developed, it is quite functional.
The smallest crustaceans-Daphnia (they are still called by the name of one of the most common species of Daphnia — crustaceans bosmin). Because of their small size (from two to six millimeters), they are also called water fleas. In their diet — bacteria and small algae. Breathe gills, which are placed on the front legs. The genome of these tiny crustaceans has 5,000 more genes than humans.
Crustaceans do not allow water to get dirty, because their diet includes dead fish and other organic residues. So cleaning from falling in the water to breed harmful bacteria and inhabitants of the pond less likely to get sick.
Shellfish are eaten with shells so that the body receives calcium-the building material for the shell.
Crayfish in the water are green, gray or blue. Red color after they are cooked, due to the fact that the pigments of all colors from the boil disintegrate, there is only red, resistant to heating. This red pigment is not formed in the process of boiling, it is constantly present in the cancer shell, it is simply not visible against the background of other colors, they form a total color that allows you to mask well in river water. Unfortunately, such a barbaric way of crayfish as boiling alive is often practiced. In the past, it was believed that crayfish and shrimp do not feel pain. In fact, this is not the case, they feel pain, this is confirmed by scientific research. Perhaps this fact will change our attitude to the way of cooking crayfish and shrimp.
Crayfish carry caviar under the abdomen, which is incorrectly called a tail. The clutch reaches 600 eggs and takes about six months from laying the eggs until the babies are born. After birth, small crustaceans for two weeks are on the mother in the same place where there was caviar and eat the remnants of food from the mother. It is possible that the mother specifically leaves the kids something to eat, and not so it remains — just shredded food.
Crayfish retreat when they go into a hole or retreat, so it is more convenient for them to defend themselves. If they walk on the bottom of a pond, they go headfirst. Also, crayfish, if necessary, such as hunting, can move very quickly, they are not always as slow as we know them.
In the summer of cancer likes to spend time in shallow waters, sometimes goes ashore, if he sees food on it (e.g., falling). Winter lives in burrows, under stones or in other natural havens.
The largest individuals in Russia and Ukraine reach a length of 20 centimeters and a mass of 200 grams. Life expectancy-up to 20 years. The largest crayfish vodayutsya on the island of Tasmania, their length - up to 60 centimeters, weight - up to 600 grams.
Sea
Interesting facts about crustaceans living in the seas and oceans. The record for the size of crustaceans-sea spider, which is called a giant. It is a crab whose claws reach a length of four meters.
There are 500 species of crustaceans in the Black sea. The most famous — shrimp and crabs, their meat is considered a valuable protein product, which has in its composition a lot of useful trace elements, easily absorbed and therefore considered dietary.
Shrimps are very large, tiger shrimps reach a length of almost 40 centimeters (this is a record size, on average-30 centimeters).
Hermit crab does not have a shell, he is looking for shells without the owner, and such that it suited the size. When the house gets cramped, he changes it for a bigger one.
Lobsters can live a long time (perhaps up to a hundred years) and reach considerable size (a record of 20 kilograms).
Among crabs the biggest-Japanese a giant. The trunk reaches 30 centimeters in diameter, while the legs are very long-more than one meter.
Sea crayfish-lobsters carry eggs for a whole year.