The front half of the body of the squid is flattened disc-shaped, the tail is cylindrical, generally 40 to 60 cm long, weighing 300 to 800 grams, living under the temperate seabed, the squid is generally benthic, lying on the seabed or slowly moving, the squid has a large appetite, it grows in the depths of the dark sea, the body is slender and pointed backwards into a column, two eyes are born on the top of the head, a blood basin with a large mouth as wide as the body, the skeletal fish is a teleost fish, the edge of the mouth has a row of sharp teeth with a tip inward; the ventral fin grows in the throat. The pectoral fin on the side of the body has an arm, the large mouth has two rows of hard teeth, and the sturgeon uses the fin spines on the top of its head as bait. The head is particularly large and flattened, the mouth is wide, there are black and white markings in the mouth, and the lower jaw has 1 to 2 rows of fangs that can be collapsed. The body is soft and scaleless, with a brown back and a grayish-white ventral surface. There are many cortical protrusions on the edges of the head and body. There are 6 separate fin spines in the anterior part of the dorsal fin, the first spine is located on the back of the snout and has a cortical spike at the tip; the pectoral fin is wide and arm-shaped on both sides of the body; and the fin has 8 to 11 fins. Each fin is dark brown.
The first dorsal fin is different from that of ordinary fish, consisting of 5 to 6 independently separated fin spines (6 are yellow sturgeon and 5 are black squid). The first two are located on the back of the snout. It has cortical spikes at the apex. The second dorsal fin and the arm fin are both located at the tail. The pectoral fins are wide, lateral, rounded, and the base is arm-shaped, which facilitates the body to slide. The ventral fin is short and laryngeal. The caudal fin is rounded and truncated. The body is bare and scaleless , with cortical protrusions of varying sizes above the head and on the lateral edges of the body. The front end of the sturgeon is flattened in the shape of a disc, and the total length of this trout is only 10 cm. It is not likely to encounter prey in the deep sea, and try to swallow as much food as possible to be larger than yourself. Sharp teeth are inward and once prey is caught, it will not be allowed to escape. The sturgeon is less swimming and has few predatory opportunities, and over the course of its long evolution, its dorsal fin changes: the first dorsal fin gradually extends towards the head, and the first three spines of the dorsal fin are separated in a silky way in front of the head, and there is a glowing flap at its end. When the small fish swims near the flash point, the sturgeon shakes its fishing gear, hooks the fish, and sends it into the mouth.
Above the head of the trout there is a fleshy protrusion, shaped like a small lantern, which is formed by the gradual upward extension of the first dorsal fin of the trout. The reason why the small lantern emits light is because it has glandular cells in the lantern that can secrete photons, which emit light by slow chemical oxidation with oxygen under the catalysis of photonase. Many fish in the deep sea have phototropism, so the small lantern becomes a weapon for the trout to lure food.
Male trout grow in the depths of the dark sea, slow movement, much smaller than the female, and do not live in harmony, in the vast ocean male fish is difficult to find the female fish, once encountered with the female, it bites through the female belly tissue, burrowed into its skin, lifelong attachment to death, the male fish lifelong nutrition is also provided by the female fish. Over time, the trout formed this unique mate relationship.
In order to survive, male anglerfish must find a female fish and parasitize the female's body. They bite the female, release an enzyme that dissolves the skin tissue and binds to the female.
In this way, the semen of the male fish enters the female's body while obtaining the female's nutrients. However, the male soon dies, leaving only a clump of testicles, ready to fertilize the eggs when the female ovulates.
Scientists have found female anglerfish with 8 clusters of testicles on their bodies. For those males who do not find a female, they will take another approach, that is, to change their sex to the female and wait for the male to appear.
The cross-tail behavior of the striped squid is short and interesting. The female excretes a number of gelatinous eggs that are used to adsorb male sperm floating with the seawater. Subsequently, the fertilized egg floats to the surface for several days and then sinks to the bottom of the sea until the fetus hatches. A small number of sturgeon are found off the coast of southern Australia, and they mate in another way. This smooth-skinned female releases fewer but larger eggs than other species of catfish. After mating, one side cares for the fertilized eggs until they hatch into fish. The guardian male or female uses plump, endearing fertilized eggs to lure curious prey into the bait and devour them in one fell swoop. The sturgeon is found in tropical and subtropical waters around the world, but this fish, which is adept at sneaking prey, still needs human protection because its habitat is deteriorating.