The Sox9 gene of Acipenser sturio, one of the most primitive vertebrates, was analyzed. No sex-specific differences were observed. Sturgeon Sox9 consists of three exons and two introns with completely conserved exon-intron boundaries showing high levels of homology to other vertebrate Sox9 sequences, especially in the N-terminus region containing the HMG box. We found strong evidence for negati...

A newly discovered virus, Namao virus, associated with morbidity and mortality, was detected among juvenile lake sturgeon Acipenser fulvescens being propagated by a conservation stocking program for this endangered species in Manitoba, Canada. The outbreaks resulted in cumulative mortalities of 62 to 99.6% among progeny of wild Winnipeg River or Nelson River lake sturgeon and occurred at 2 geog...

Green and white sturgeon are species of high conservational and economic interest, particularly in the San Francisco Bay Delta (SFBD) for which significant climate change-derived alterations in salinity and nutritional patterns are forecasted. Although there is paucity of information, it is critical to test the network of biological responses underlying the capacity of animals to tolerate curre...

Ribosomal DNA in sturgeon is informative when analyzed at the molecular level because it bears unique characteristics that are, to a certain extent, ancestral within vertebrates. In this paper, we examine the structure and the molecular evolution of the 5S ribosomal DNA (rDNA) region in 13 sturgeon species, comparing both the 5S ribosomal RNA (rRNA) genes and the non-transcribed spacer (NTS) se...

The white sturgeon, Acipenser transmontanus, is a primitive bony fish that is recognized as an important emerging species for aquaculture. However, many aspects of its stress and reproductive physiology remain unclear. These processes are controlled by various steroid hormones. In order to investigate the regulation of steroidogenesis associated with acute stress in sturgeon, a cDNA-encoding st...

The utility of genetic measures for kinship reconstruction in polysomic species is not well evaluated. We developed a framework to test hypotheses about estimating breeding population size indirectly from collections of outmigrating green sturgeon juveniles. We evaluated a polysomic dataset, in allelic frequency and phenotypic formats, from green sturgeon to describe the relationship among know...

Worldwide, populations of sturgeons are endangered, and it is hypothesized that anthropogenic chemicals, including dioxin-like compounds (DLCs), might be contributing to the observed declines in populations. DLCs elicit their toxic action through activation of the aryl hydrocarbon receptor (AhR), which is believed to regulate most, if not all, adverse effects associated with exposure to these c...

sperm morphology, biochemistry and physiology were compared between siberian sturgeon Acipenser baerii and sterlet A. ruthenus in the present study. We observed wide morphological variations between spermatozoa of the two species. the average length of the spermatozoon head was 7.01 and 5.14 μm in A. baerii and A. ruthenus, respectively. Significant differences were observed in terms of Na+, k+...

is a landlocked population restricted to a 270 km stretch of the Kootenai River, which flows from western Montana through northern Idaho and into British Columbia. This population has shown an almost complete lack of natural juvenile recruitment since 1974. The total adult population in 1998 was estimated to be about 650 individuals and this fish is currently classified as endangered by the Ida...

To increase the understanding of lake sturgeon (Acipenser fulvensens) in the upper Mississippi River a radio telemetry study was conducted in Pools 4 through 10. Currently lake sturgeon are listed as a species of concern. GIS analysis of available data was performed to determine the spatial relationships that exist between lake sturgeon and their habitat. Aquatic type, wing dam, revetted dam, a...