Shrimp is a crustacean decapod swimming suborder with nearly 2000 species, most of which live in rivers and lakes. They all have beards, hooked noses, jointed back arches and hard scales at their tails, so they are good at jumping. Many kinds of food are important. The size varies from several meters to several millimeters, with an average of 4 ~ 8 cm. The big one is called prawn.

shrimp

Shrimp swimming is very different from fish. Fish can swim forward by swinging their tail fins. Shrimp has no tail fin like fish, only a tail and many calves. So how does it swim? Shrimp also has its "coup". Shrimp is a good swimmer and can swim long distances with its legs. When it swims, its swimming feet paddle backward frequently and neatly like wooden paddles, and its body drives forward slowly.

When frightened, its abdomen bends and stretches flexibly, its tail strokes down and forward, and it can jump backwards continuously at an extremely fast speed. Some shrimps are not good at swimming, and big lobsters spend most of their time crawling on the sand and stones on the seabed. The gills of shrimp with respiratory circulation are located in gill chambers formed on both sides of the crustacean, and the gill chambers are communicated with the outside world.

The jaw boat in the gill chamber swings constantly, so that fresh water enters from the back and abdomen and flows forward. The circulation system is open. The heart is a flat polygonal muscle sac located in the pericardial sinus behind the head and chest. There are four pairs of cardiac holes, two in the back, one on both sides of the posterior end and the other on the ventral side of the heart near the posterior end. There are valves that control blood flow.

Refer to the above content: Baidu Encyclopedia-Shrimp