Elephant-nosed fish
Elephant-nosed fish is the living white sturgeon. A very ancient sturgeon, the Elephant Nose Fish is now endangered due to its very special shape, overfishing by humans and other reasons. The Elephant Nose Fish is now no less endangered than the giant panda. So what is so special about the shape of the elephant-nosed fish?
The Elephant Nose Fish belongs to the genus Elephant Nose Fish in the family Acipensidae of the order Acipensariformes. It is named because of its lighter body color. Also known as harp fish and sword fish, its ancient name is tuna. The body is long and fusiform. Both the left and right jaws have pointed teeth. The snout is long and sword-shaped, 1.5 to 1.8 times as long as the back of the eye. The snout gradually becomes wider from front to back. The front end is blunt and pointed, narrow and flat, and the base is fat and thick. The body has no bony plate-like large hard scales; there is only a row of spiny scales on the upper edge of the caudal fin, the back is light purple-gray, and the abdomen and each fin are slightly white-pink. It has important academic value in the origin, evolution and geographical distribution of fish.
In terms of body structure, the body of the elephant trunk fish is spindle-shaped, with the front part slightly flat, the middle part strong, and the rear part slightly flattened laterally. The head is extremely long, more than half the body length, and is covered with plum blossom-shaped traps. The ventral surface of the head of the snout can expand and contract freely. There is a record in old books that "the mouth of tuna is under the jaw and the cartilage of the nose is long", which briefly summarizes the ecological characteristics of elephant-nosed fish. The left and right jaws have small, pointed teeth; the snout is a pair of short, short, located on the ventral surface. The eyes are small, with a pair of tiny whiskers located on the ventral side of the snout. The mouth cleft is large, arc-shaped, stretchable, and located on the ventral surface of the head. There are 2 external nostrils on each side of the head. The surface of the entire head membrane is densely covered with many fine plum blossom-like sensory nerve cell structures. The lateral line of the body is complete, the tail is crooked, the upper lobe is long, the lower lobe is short, there are spiny scales on the back of the upper lobe, and the body surface is smooth and scale-free. There are 8 prismatic scales on the upper lobe of the caudal fin, extending backward to the upper lobe of the caudal fin. The dorsal fin begins behind the pelvic fin and is composed of unbranched rays. The caudal fin is crooked, the upper lobe is prosperous, and the front edge has a row of spinous scales. The intestine is short and has 7 to 8 spiral valves in the intestine. The head, body back and tail fin are blue-grey, and the abdomen is white.
</p>
</p>