The lamprey belongs to the genus lamprey of lampreys. The skin is bare and the surface is smooth and scale-free; The mouth is cylindrical without upper and lower jaws, and there are sharp teeth in the mouth; There are spikes on the edge of the mouth funnel, and most of the horny teeth in the mouth funnel are separated and scattered, not paved with stones, and sometimes arranged radially like fluff. Behind the nostril, there is a pineal eye peculiar to the class Cirrhostoma.
There are 7 pairs of slightly oval gill holes behind the eyes, and 7 pairs of gill holes are arranged in a row behind the eyes. Life span is 7 years. Lamprey is distributed in Heilongjiang, Wusuli, Tumen and Songhua rivers in the northeast of China. Migratory fish, which live in the sea for some time, swim to fresh water rivers to lay eggs after growing up. Carnivorous fish.
Live independently and live parasitically. When the camp lives independently, it eats zooplankton. Parasitism often absorbs on other fish with sucker and sucks their flesh and blood. When breeding, shallow water, fast flow and gravel pit are selected to nest and lay eggs, and the eggs are extremely small, with 80,000-/kloc-0,000 eggs each time, and all the parent fish die after laying eggs.
Lamprey fish can be used as medicine, which is sweet and warm, and has the effect of nourishing and strengthening the body. It is often used to treat mouth and eye deviation, night blindness, corneal dryness and other diseases. The lamprey is one of the last jaw-less vertebrates in the world. Its fossils prove that it had existed on the earth for hundreds of millions of years before dinosaurs appeared, and it is called a living fossil, which is of great significance for studying biological evolution. ?
morphological character
The lamprey looks like an ordinary eel, with a slender body, an eel-shaped, bare and scaleless skin, and a long dorsal fin on its back, which extends backwards to the tail and forms a caudal fin around the tail. Besides, there are no other fins on its body. 2 dorsal fins, well-developed mouth funnel, no mouth whiskers. The lamprey has only one nostril, which is located between the eyes on the top of the head.
Developed eyes, pinecone eyes, with photosensitive effect. It has seven gill holes on both sides of its body behind its eyes, which is why it is called lamprey. The inner ear has two semicircular canals. At the end of the nasopituitary capsule is the blind capsule. Dioecious, it takes a long larval period to develop and metamorphoses into an adult. Adults live a semi-parasitic life, which is harmful to fisheries.