Scaphirhynchus platorynchus
shovelnose sturgeon

Shovelnose sturgeons are a freshwater species historically found in most portions of the Mississippi and Missouri river basins. This area ranges from Montana south to Louisiana, and from Pennsylvania west to New Mexico. However, shovelnose sturgeons are no longer found in Pennsylvania, New Mexico, and large parts of Kansas, Kentucky, and Tennessee where they were once abundant. The main cause for the restriction of range is the construction of dams on many of their native waterways. ("Mississippi Interstate Cooperative Resource Association", 2004)

Shovelnose sturgeons are primarily bottom dwellers, preferring high turbidity in large waters, and are usually found in pools downstream of sandbars or along the main channel border. The flowing freshwater is between 18-20 deg C. During low water or in the warm summer months, these sturgeons seek cooler, deep channel areas. ("Mississippi Interstate Cooperative Resource Association", 2004; Keenlyne, 1996; Kynard, Henyay, and Horgan, 2002; U.S. Fish and Wildlife Service, 2004)

Shovelnose sturgeons have an elongated body with five rows of sharply keeled body plates: 14-19 dorsal plates, 38-47 lateral, 10-14 ventrolateral. They are olive to yellowish-brown in color on the top with lighter sides, and white on the bottom. The head contains bony plates with short spines at the tip of the snout and anterior to the eye. The snout is rounded and pointed up. The caudal peduncle is long, depressed, and fully armored. The tail is heterocercal, with the upper lobe containing long, thread-like filaments. All four barbels are evenly spaced under the jaw, unlike the related pallid sturgeon, which has barbels unevenly spaced under the jaw. The most readily distinguishing characteristic of the shovelnose is its small size and dark color. They rarely exceed 5 lbs (2.3 kg) or over 28 inches (70 cm)in length. (U.S. Fish and Wildlife Service, 2004; US Fish and Wildlife Service, 2004)

Eggs are deposited over cobble, gravel, or rock, becoming adhesive and attaching to the bottom substrates. After five to eight days, the eggs hatch and the young begin to search for food on the river bottom. Females grow significantly faster than males. (Everett and Scarnecchia, 2003; U.S. Fish and Wildlife Service, 2004)

The largest shovelnose sturgeon recorded weighed 13.72 lbs (6.2 kg). Most are not expected to live over 30 years of age. (US Fish and Wildlife Service, 2002)

Eggs are deposited on rocky substrates, providing protection for young shovelnose sturgeons to develop in safety. As the young mature they begin to travel greater distances away from their natal habitat. Females grow significantly faster than males, enabling them to travel further earlier. These fish spend their lives swimming near the bottom over cobble or gravel substrates in fast, turbid water, feeding mostly on invertebrates. (Everett and Scarnecchia, 2003; U.S. Fish and Wildlife Service, 2004)

The behavior of S. platorynchus is highly adapted for life in the current. They spend most of their lives, except during spawning, on the river bottom in deep, cool channels. The current makes it easier to find food, and their specialized siphon-like mouths act like vacuums, sucking up organisms buried in the benthic substrates. They have a wide home range, and can travel large distances in one day searching for food. Increased water flow seems to trigger the behavior to move upstream. Usually they are not found in large groups, except during breeding. (Bradshaw, 1998; US Fish and Wildlife Service, 2002; US Fish and Wildlife Service, 2004)

Home Range

The shovelnose sturgeon can travel up to 20 km in one day, however, most patrol a much smaller range in the search for food. Home range is not set for their entire lifetime, and can change as food abundance or alteration in habitat occurs. (US Fish and Wildlife Service, 2004)

Shovelnose sturgeons search for food by manipulating their large barbels which have taste buds and electrorecptors. These barbels hang below the mouth and feel the bottom as the sturgeon swims. This allows them to sense when food or other obstacles are below. (Bradshaw, 1998; U.S. Fish and Wildlife Service, 2004)

Scaphirhynchus platorynchus are opportunistic feeders, eating mostly aquatic insects, mussels, worms and crustaceans. Altered stream flow can affect the sturgeon’s ability to find food and also influences the abundance of prey organisms. The barbels detect prey, and then the sucker type mouth easily picks up the food organisms. Most food is found over sand and gravel substrates. ("Mississippi Interstate Cooperative Resource Association", 2004; Keenlyne, 1996; U.S. Fish and Wildlife Service, 2004; US Fish and Wildlife Service, 2002)

Other fishes, such as catfishes and burbots, probably eat the young shovelnose sturgeons. The main predator of adult shovelnose sturgeons is man. Presently, about 25 tons of shovelnose sturgeon are harvested annually. Sixty percent come from the Mississippi River upstream of St. Louis, Missouri. They are harvested in late fall and early winter for both meat and highly valued roe. The alteration of large rivers, and construction of locks and dams for navigational purposes has contributed significantly to the decline of the species by blocking access to ancestral spawning grounds, and by eliminating its required habitat. (Bradshaw, 1998; Keenlyne, 1996; US Fish and Wildlife Service, 2004)

Scaphirhynchus platorynchus feed on invertebrates, stirring up and loosening bottom substrates. The shovelnose sturgeon harbors a newly discovered virus called the Missouri River Sturgeon Iridovirus or MRSIV. The shovelnose sturgeon is host to the hickory-nut Obovaria olivaria, and may possibly be hosts for other pearly mussels including commercial species. Lamprey also parasitize the fish. (U.S. Fish and Wildlife Service, 2004; US Fish and Wildlife Service, 2004)

There are no known adverse affects of shovelnose sturgeons on humans.

Shovelnose sturgeons have many benefits to humans. They have been commercially harvested since 1987, and the meat is considered a delicacy, especially when smoked. They are also considered a sport fish in 12 of the 24 states in which they occur. The roe is used as an acceptable caviar and it has also been introduced as a potential aquarium fish. ("Mississippi Interstate Cooperative Resource Association", 2004; Keenlyne, 1996; U.S. Fish and Wildlife Service, 2004)

Shovelnose sturgeons are considered extirpated in three states, fully protected in four, and rare, or of special concern in eight states as of 1996. However, they are not currently listed as federally threatened or endangered. (Keenlyne, 1996)

Rafinesque described this species as the 97th species described in his book, "Ichthyologia Ohiensis: Natural History of the Fishes Inhabiting the River Ohio and Its Tributary Streams," published in 1820. (Evansville education, 2004)