| ||Scaphirhynchus rafinesquii Heckel, 1836: 72, Pl. 8.|
|En - Shovelnose sturgeon, Fr - , Sp - .|
3Alpha Code: PHF Taxonomic Code: 1170100401|
|Scientific Name with Original Description|
|Accipenser platorynchus Rafinesque, 1820. Western Rev. Misc. Mag. v. 3, no. 4:244-252. Ohio, Wabast and Cumberlands Rivers, USA.|
|Spiracle absent. Snout flat, spadelike. Caudal peduncle depressed, long, and completely armed. Mouth small, transverse. Lower lip continuous, with 4 lobes. Branchiostegal connection narrow. Eye very small. Barbels with accesory fringe, evently placed.
D:29-36; A:18-24 rays.
13-19 (common 14-18) dorsal scutes. 38-50 (42-46) lateral scutes, that are tilted forward anteriorly. 9-14 (11-14) ventral scutes. with 8-9 scutes posterior to both, dorsal and anal fins. 4-6 scutes between anus and anal fin. With preorbital spines and with 1-17 spines on the dorsal tip of the snout. Spines significantly larger that those present in homologous areas of S. suttkusi. Belly and breast of specimens larger than 20 cm, completely armored with subrhombic plates, becoming much smaller forward.
Pale olive, darker above, where the color is often a yellowish brown. Belly whitish (Forbes & Richardson, 1908).
|Habitat and Biology|
|Sholvenose sturgeon are primarily a bottom dwelling species.Usually found in association with sand substrate, often near rock or gravel; they live where there is a current of 20-40 cm /s being usually found in pools dowstream from sandbars in unchanalized rivers, along the main channel border, downstream from dams, or in association with wing dams in rivers navigational training structures (Keenlyne, 1997).Oportunistic feeder that prey on aquatic invertebrates, primarily on inmature insects. By frequency, the most important food items of this species are Diptera, Trichoptera, Ephemeroptera, Odonata, Plecoptera, other insects, other invertebrates and plants.|
Spawning habits of sholvenose sturgeon has not been described. Spawning is believed to occur over hard substrate in primary tributary streams to the main rivers, or along the border of the amin river channels. The capture of specimens in spawning condition indicates that this occur from late April to June. Egg are adhesive and requires current for proper development. Most males become sexually mature at age 5, while most females do not mature until age 7. In areas of poor food supply, males and females become sexually mature at a smaller size. Following sexual maturity is influence by food supply and ability to store adequate fat to produce mature gametes (mostly fom Keenlyne, 1997 and Mayden & Kuhajda, 1996).
Few individuals probably exceed 12-15 years of age.
|Maximum size: 86 cm TL. Maximum weight: up to 7 Kg (Keenlyne, 1997). Usually less than 2.5 Kg.|
|Interest to Fisheries|
|Sport fish in 12 states of the USA. Commercial harvest data about 25 tons each year (Keenlyne, 1997).|
Lopatonos amerykanski .|
|UNITED KINGDOM :
Shovelnose sturgeon ,
Sand Sturgeon .|
Shovelnose sturgeon .|
Bailey, R.M & F.B. Cross - 1954River sturgeons of the American genus Scaphirhynchus: characters, distribution and synonymy. Pap. Michigan Acad.Sci., Arts and Letters .
Birstein, V.J., Bemis, W.E & J.R. Waldman - 1997. The threatened status of acipenseriform species: a summary. Environm. Biol. Fish. .
Carlson, D.M., W.L Phliegger, L. Trial & P.S. Haverland - 1985. Distribution, biology, and hybridization of Scaphirhynchus albus and S. platorynchus in the Missouri and Mississippi rivers. Environ. Biol. Fish. .
Cross, F. B. - 1967. Handbook of fishes of Kansas. Mus. Nat. Hist., Univ. Kans., Miscel. Publ. .
Helms, D.R - 1974. Age and growth of the sholvenose sturgeon, Scaphirhynchus platorynchus (Rafinesque), in the Mississippi River. Proc. Iowa Acad. Sci. .
Keenlyne, K.D. - 1997. Life history and status of the sholvenose sturgeon, Scaphirhynchus platorynchus. Environ. Biol. Fish. .
Mayden, R.L. & B.R. Kuhajda - 1997. Threatened fishes of the world: Scaphirhynchus suttkusi Williams & Clemmer, 1991 (Acipenseridae). Environ. Biol. Fish. .
Mayden, R.L. & B.R. Kuhajda - 1996. Systematics, taxonomy, and conservation status of the endangered Alabama sturgeon, Scaphirhynchus suttkusi Williams and Clemmer (Actinopterygii, Acipenseridae). Copeia .
Modde, T. & J.C. Schmulbach - 1977. Food and feeding behavior of the shovelnose sturgeon, Scaphirhynchus platorynchus, in the unchannelized Missouri River, South Dakota. Trans. Am. Fish. Soc. .
Page, L.M & B.M. Burr - 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. .
Williams, J.D & G.H. Clemmer - 1991. Scaphirhynchus suttkusi , a new sturgeon from the Mobile Basin of Alabama and Mississippi. Bull. Alabama Mus. Nat. Hist. .