Dietary assessment of age-0 pallid sturgeon and shovelnose sturgeon: implications for surrogacy

Genetic evidence for hybridization of pallid and shovelnose sturgeon.

To determine the genetic origin of individual sturgeon that are morphologically intermediate to pallid (Scaphirhynchus albus) and shovelnose (Scaphirhynchus platorhynchus) sturgeon, we combined previously published mitochondrial DNA (mtDNA) and microsatellite data with additional microsatellite data. Two sympatric populations of pallid and shovelnose sturgeon from the upper Missouri River and a...

Critical Swimming Speed and Behavior of Juvenile Shovelnose Sturgeon and Pallid Sturgeon

The swimming performance of hatchery-reared. juvenile shovelnose sturgeon Scaphirhynchus plarorynchus and pallld sturgeon S. albus was studied in a laboratory swim tunnel at 20°C and 1O0C. The mean 30-min critical swimming speed was not significantly different between species at either temperature (36.9 crd s for shovelnose sturgeon and 35.9 cm/s for pallid utur-geon at 20°C. 19.4 cmls for shov...

Reproductive Isolation in Sympatric Populations of Pallid and Shovelnose Sturgeon

—Pallid sturgeon Scaphirhynchus albus and shovelnose sturgeon S. platorynchus are recognized morphologically as separate species. A previous genetic study with allozymes was unable to distinguish between the two species or demonstrate their reproductive isolation in regions of sympatry. Our main objective was to measure the genetic variability within and among populations of pallid and shovelno...

Vulnerability of age-0 pallid sturgeon Scaphirhynchus albus to fish predation

Use of Ultrasound Imaging to Determine Sex of Shovelnose Sturgeon

—During November 2002, 51 shovelnose sturgeon Scaphirhynchus platorynchus were sexed by ultrasound imaging using a portable ultrasonograph. We identified males with 96% accuracy (N 5 25) and females with 80% accuracy (N 5 25); one hermaphroditic individual was misidentified as a male. Overall, ultrasound imaging was 86% accurate. Sex in postspawned females was difficult to determine, 60% being ...