A small isolated population of beluga whales (Delphinapterus leucas) that are highly contaminated by pollutants, mostly of industrial origin, resides in the St. Lawrence estuary, Québec, Canada. Overhunting in the first half of the century was the probable cause for this population to dwindle from several thousand animals to the current estimate of 500. The failure of the population to recover ...

—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 ...

The aim of this study was to provide comprehensive insights into the genetic background of sturgeon by transcriptome study. We performed a de novo assembly of the Amur sturgeon Acipenser schrenckii transcriptome using Illumina Hiseq 2000 sequencing. A total of 148,817 non-redundant unigenes with base length of approximately 121,698,536 bp and ranges from 201 to 26,789 bp were obtained. All the ...

Little is known regarding molecular mechanisms involved in sex determination and differentiation in sturgeon species. We addressed this knowledge gap by using next generation pyrosequencing technology to provide transcript libraries and species-specific sequences for mature gonads of shovelnose sturgeon, Scaphirhynchus platorynchus. We then mined these libraries to identify gender-specific tran...

Characteristics of the in vitro propagation of the white sturgeon iridovirus (WSIV) were examined in 6 sturgeon cell lines. One new cell line originating from gonadal tissues (WSGO) produced up to 12-fold more WSIV [approximately 22 TCID50 (50% tissue culture infective dose) cell-1], than that of a previously established reference spleen cell line (WSS-2). Infected WSGO cell cultures were exami...

TheRussian sturgeon,Acipensergueldenstaedtii, is closely related to three other sturgeon species (A. persicus, A. naccarii and A. baerii), with populations in the Caspian Sea containing a cryptic lineage with an A. baerii-like mtDNA profile. Using morphological evidence (morphometrics, meristics) and additional genetic analysis (cytochrome b gene and control region sequencing), cryptic lineages...

The influence of nanoparticles (NPs) on aquatic environments is still poorly documented. The aim of the study was to determine the effects of silver (AgNPs) and copper (CuNPs) nanoparticles on larval Siberian sturgeon (Acipenser baerii) after 21 days of exposure. Acute toxicity of AgNPs on Siberian sturgeon was investigated in a 96-h static renewal study and compared with the toxicity of CuNPs....

Enzymatic antioxidant activities (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase) and lipid peroxidation were determined in different tissues (gills, heart, digestive tract, liver, white muscle, skin, red blood cells, swimbladder) of trout (Oncorhynchus mykiss) and sturgeon (Acipenser naccarii). Total tissue antioxidant activity was, except for catalase, generally...

A phylogenetic hypothesis is presented illustrating relationships among 23 extant sturgeon species based on nucleotide data from five mitochondrial genes (cytochrome b, NADH5, control region, 16S, and 12S). The tree supports our previous hypotheses regarding relationships among species of Acipenser and Huso. The introduction of Scaphirhynchus and Pseudoscaphirhynchus to the analysis does not ch...