North American paddlefish, Polyodon spathula, lives in the central United States. Although the fish is still plentiful in many rivers and lakes, any dam building is certain to disrupt its breeding cycle and jeopardize its future. Because individuals can live to thirty years of age, the effect of this loss of breeding grounds will not be noted until it is too late. This fish is a feeder of small and tiny water animals that it filters from the water by swimming around with its mouth open. Adult fish reach five feet and weigh up to forty pounds.

The commercial importance of this fish is declining. However, in l899 the total annual harvest was estimated at about 2,500,000 pounds. Although the fish will not take a conventional lure, it is captured by sport fisherman by a method called snagging.

Pflieger notes in his book on Missouri fishes that records exist for specimens over 160 pounds and lengths of about 7 feet. He notes that MIssouri populations have experienced a drastic decline since 1900. He noted that large populations were still present in Lake of the Ozarks and the Osage River. Missouri estimates that the annual sport fishing catch is about 200,000 pounds.

Paddlefish group contains but two species of fish. One giant creature, the Chinese paddlefish, attains a length of twenty-two feet. The other species lives in North America.

Sturgeon and paddlefish group (Order Chondrostei) contains the Bichirs, Sturgeons, and Paddlefish. Note that although this group is placed with the cartilage fish group, sturgeons do have bones. This small group of fish could be placed in several different taxonomic places (with the sharks or with the modern bony fish).

Sharks and rays (Elasmobranchi), cartilaginous fishes, deserve to be a class separate from the normal fish, in that they do not have a bone skeleton but rather a cartilage skeleton.

Fertilization is internal in this class which also separates them from the bony fish class. Although there are a few fresh water species, the majority of the species in this class are found in salt water. As of 2005, there were about 500 known species of sharks and about 600 known species of rays.

David Ebert, author of a recent book on sharks, rays, and chimaeras of California, counts a total of 988 described species in the class with about 150 additional species awaiting scientific description. He breaks down the described species to 410 species of sharks, 543 species of rays, and 35 species of chimaeras.

Many species of sharks face an uncertain future, as the Chinese purchase shark fins to make shark fin soup. It was estimated that 100 milllion sharks are killed each year for this purpose. However, recent estimates indicate the Chinese are reducing their consumption of this exotic soup.

Backboned Animals (Phylum Chordata) are the most advanced group of animals on earth. These animals are characterized by having a spinal cord or backbone. Most members have a clearly defined brain that controls the organism through a spinal cord. Fish, amphibians, reptiles, birds, and mammals are in this phylum.

Currently, some taxonomists believe that the fish should be divided into two groups (sharks and regular fishes) and that there are some other primitive groups in the phylum such as hagfish or lampreys.

Animal Kingdom contains numerous organisms that feed on other animals or plants. Included in the animal kingdom are the lower marine invertebrates such as sponges and corals, the jointed legged animals such as insects and spiders, and the backboned animals such as fish, amphibians, reptiles, birds, and mammals.

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