Water Magazine No. 23 Mississippian Shell

The Mississippian shellfish is one of the largest freshwater fish: according to experts, its length can reach 3 m with a weight of over 130 kg. The average life span of fish is 40 years. They have a torpedo-shaped body, adults have wide heads, short wide muzzles and a double row of sharp teeth on the upper jaw. The teeth of the lower jaw enter the grooves between the two upper rows. The color of the fish is usually brown or olive with a lighter gray or yellow abdominal surface. The skin is covered with a layer of thick, diamond–shaped and almost impenetrable scales - it does not lend itself to a knife. She protects Gar's alligator from real alligators. Adult carapaces have no other enemies (except humans). The jaws are also special, you can compare them with a beak. They help the fish capture and hold prey before swallowing. The peculiarity of the Mississippian shell is the amazing structure of the internal organs. Unlike most other fish species, the shell has a developed vascular network of the swim bladder. Blood vessels run throughout the swim bladder and connect to the esophagus. Thus, the bubble not only provides buoyancy, but also allows the fish to breathe air. Therefore, they can inhabit reservoirs in which most other fish would die of suffocation. Fish have a long life and late maturation. The fertility of females is high – 4.1 eggs per gram of body weight. After a couple of weeks, the independently living fry already feed on plankton, invertebrates, amphibians and fish.

The area

The adjective "Mississippian" in the name of the fish indicates its main habitat. The natural distribution range is the lower reaches of the Mississippi River, the Gulf coast of the southern United States and Mexico. The alligator pike is considered an ancient or primitive representative of aquatic species, since its existence dates back to prehistoric times. They are often called "living fossils". The physiology of the Mississippian shellfish comes from its ancestors. They are members of an ancient order of finned fish that has existed since the end of the Cretaceous period, hundreds of millions of years ago, when dinosaurs still walked the Earth.

Food

Mississippian shellfish have a very good appetite. Prey trapped in powerful jaws is first captured across the body (Fig. 8), and then turns its head to the throat in short lateral jerks and is swallowed. The same principle of capturing prey during hunting is used by an ordinary pike. Adults eat everything they come across. Fish, turtles, crustaceans, birds, small mammals, and sometimes carrion – everything gets on the dining table of this predator. For hunting, the fish uses the ambush method. She lurks somewhere in the river thickets, waiting for the victim, and then with a sharp lateral movement captures the prey with her jaws. Young fish usually hunt collectively. They drive the victim to the riverbank, pounce on it and eat it. 

Relationship with a person

Perhaps the deadliest enemy of this fish is man. Despite their fearsome size and predatory behavior, not a single case of Mississippian shellfish attacking humans has been reported. Industrial activities such as dam construction and dredging, as well as uncontrolled fishing, have led to the destruction of the natural habitat of these freshwater inhabitants and to the extermination of the alligator pike in most of its historical range. For almost half a century, the alligator pike has been considered a "garbage fish" that should not be caught because of its bones and tough scales, as well as a "harmful species" due to its tendency to hunt sport fish. However, many are still trying to catch the Mississippian Shellfish and appreciate its fighting abilities. Despite this, the alligator pike plays an important ecological role as apex predators on many waterways. Alligator pikes have been granted protection through limited fishing licensing.

Skull

  A giant specimen of the Mississippian shellfish in March 1910