Report on the topic: “Crustacean”

A message about crustaceans, summarized in this article, will tell you about aquatic animals of this species.

Report on the topic: “Crustacean”

The class of crustaceans is represented by aquatic animals that inhabit fresh water bodies and seas. Their distinguishing feature is the separation of the body into the abdomen and cephalothorax, facet eyes and two pairs of antennae. They breathe with gills.

Brief description of crustaceans

First of all, it is worth mentioning which departments the body of crustaceans is divided into. It consists of the abdomen and cephalothorax. There are antennas and antennae on the animal’s head. The mutated six pairs of limbs formed the gnawing mouth apparatus: the first jaw forms the first pair, the lower jaw - the second and third pairs, the nodules - the next three pairs. They crustaceans bring food to the mouth, grind and filter it.

These animals have 5 pairs of so-called walking legs and claws, with which they protect themselves from enemies and attack their prey. Higher cancers also have abdominal limbs that perform respiratory function.

The crustacean digestive system is represented by three sections. The intestine is supplied with an important substance - chitin. It contributes to grinding food. The digestive gland is located in the stomach. Most representatives of this class lack respiratory organs, and they breathe in the thin integuments of the body. Other species breathe with skin gills. The circulatory system is open and blood circulating throughout the body is poured into the oral cavity. Crustacean dioecious animals. They care about their offspring.

Crustaceans include more than 40,000 species, which are divided into classes:

  • Squad of decapods

These include crayfish, plankton shrimps, lobsters, lobsters, and a variety of crabs. They are considered a valuable food item. Delicious dishes are made from them.

  • Detachment of Isopods

This includes terrestrial and aquatic crustaceans of gray and whitish color. They live in litter, deserts and in humid places. Representatives of this squad are small in size - up to 15 mm.

  • Squamous squad

The representative of this detachment is daphnia. She moves in leaps and for this she was popularly called a water flea.

  • Squad copepods

This order is represented by cyclops, planktonic crustacean, which feed on freshwater and marine commercial fish and a whiskered whale.

Thus, the diversity of crustaceans in nature is simply amazing. In addition to the natural habitat, humans specifically breed them in fish pond farms. Mostly these are daphnia and cyclops. The goal is the feeding of fish fry. There are also parasitic crustacean species. They parasitize on the scales and gills of fish, eating their juice.

Interesting facts about crustaceans :

  • Until the mid-19th century, lobsters were the food of the poor in America. They were used as fertilizer and bait for fish.
  • At the largest crab in the world, claws grow 4 m in length.
  • Crustaceans are natural water purifiers, as they feed on carrion: the remains of animals or dead fish.
  • Lobsters do not have an aging gene; they can live forever.
  • Crabs are very unfriendly even to their relatives. After mating with the female, if she does not run away in time, they eat her with future offspring.

We hope that the report on crustaceans helped you learn a lot of useful information about these animals. And you can add a message about crustaceans through the comment form below.

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