Stizostedion Vitreum
The walleye (Sander vitreus, synonym Stizostedion vitreum), also called the yellow pike or yellow pikeperch or yellow pickerel,[3] is a freshwater perciform fish native to most of Canada and to the Northern United States. It is a North American close relative of the European zander, also known as the pikeperch. The walleye is sometimes called the yellow walleye to distinguish it from the blue walleye, which is a color morph that was once found in the southern Ontario and Quebec regions, but is now presumed extinct.[4] However, recent genetic analysis of a preserved (frozen) 'blue walleye' sample suggests that the blue and yellow walleye were simply phenotypes within the same species and do not merit separate taxonomic classification.[5]
stizostedion vitreum
Walleye (Sander vitreus, synonym Stizostedion vitreum) is a freshwater perciform fish native to most of Canada and to the Northern United States. It is a North American close relative of the European Zander, also known as the pikeperch. The walleye is sometimes called the yellow walleye to distinguish it from the blue walleye, which is a subspecies that was once found in the southern Ontario and Quebec regions, but are now presumed extinct. However, recent genetic...
A seasonal survey of skin tumor prevalence in walleyes (Stizostedion vitreum) was conducted during the ice-free period on Oneida Lake, New York in 1986. During the survey, 1,028 walleyes were collected and examined for the presence of lymphocystis disease, dermal sarcoma, discrete epidermal hyperplasia and diffuse epidermal hyperplasia. Skin growths were high in prevalence in early spring, low in prevalence during the summer, and again high in prevalence in the fall. Lymphocystis disease and dermal sarcoma were more frequently observed than either discrete or diffuse epidermal hyperplasia. Histologically, a moderate to severe inflammatory response was associated with dermal sarcoma in the early spring and late spring but not in the fall. Regardless of the time of year, varying degrees of inflammatory response were seen associated with lymphocystis disease. Samples were inadequate to assess seasonal trends in incidence of discrete and diffuse epidermal hyperplasia.
We evaluated how two diets with different lipid levels (4% vs. 10%) influenced nutrient expenditure in juvenile walleye Stizostedion vitreum subjected to starvation, prolonged swimming, and predator presence. We also determined how exercise and predator presence influenced stress indicators such as blood plasma cortisol and glucose. Groups of six fish were placed in triplicate rectangular wire cages per treatment and submerged randomly in three artificial stream compartments at a water temperature of 14 degrees C. Three treatments were established: (A) no water current and no predator, (B) water current (1.5 body lengths s(-1)) and no predator, (C) water current and predator. Six 1-year-old muskellunge (Esox masquinongy, 28.4+/-2.3 cm) were used as predators. They were allowed to swim freely outside walleye cages and were fed with walleye. To simulate poststocking period of fasting, walleyes were exposed to experimental treatments for 6 weeks and were deprived of food. Regardless of the prior diet, fish weight significantly declined in all treatments but no differences were found among them. Lipids declined in both dietary groups of fish; in turn, body moisture increased. Protein levels were only affected in fish fed with high-lipid diet prior to the experiment and subjected to current and predator presence. Plasma glucose gradually declined in fish fed with high-lipid diet prior to the study; whereas in the fish fed with low-lipid diet before the experiment, it remained low regardless of the treatment severity. Plasma cortisol concentrations never exceeded 30 ng ml(-1) indicating no signs of acute stress during the experiment. We concluded that fish fed with diet containing higher lipid levels prior to stocking would possess better potential of withstanding adverse conditions and better survival once released to the wild.
SCHNEIDER, J. C. and J. H. LEACH. Walleye (Stizostedion vitreum vitreum) Fluctuations in the Great Lakes and Possible Causes, 1800-1975. A reprint from the Journal of the Fisheries Research Board of Canada, Vol. 34, No. 10, 1977, pp. 1878-1889. [Ottawa]: Fisheries and Marine Service, 1977. Double column. Large 8vo, blue printed card covers. Vg. 6.00
Stizostedion vitreum (Mitchill, 1818):Integrated Taxonomic Information System (ITIS) Here you will find authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world..
The scientific name for Walleye has changed recently from Stizostedion vitreum to Sander vitreus. The name has changed due to the fact that the species Zander's (Stizostedion lucioperca) genus is so closely related to that of the walleye that they are practically considered the same fish now. Since the Zander was documented first, they had to change the genus for walleye. The genus Sander remained and that is how the name changed.
Eggs from three distinct populations of walleye Stizostedion vitreum, one domesticated (London State Fish Hatchery) and two wild (Lake Erie and Salt Fork Reservoir), were compared in terms of total lipid content and fatty acid profiles (phospholipids and neutral lipids). The concentrations of total lipids in eggs from domesticated broodstock were significantly lower (8.6 1.0 % of wet weight) than those of both wild populations (13.3 0.9 % and 10.9 0.6 % of wet weight for Lake Erie and Salt Fork Reservoir, respectively). The profiles of fatty acids in egg lipids differed significantly among the three investigated populations. Domesticated females fed a formulated diet produced eggs containing significantly higher levels of linoleic acid (18:2n-6), characteristic of plant lipids. However, arachidonic acid (20:4n-6), was at significantly higher levels in eggs of wild walleye stocks. Although eicosapentaenoic acid (20:5n-3) was detected at significantly higher levels in eggs from Lake Erie walleye, docosahexaenoic acid (22:6n-3), the most abundant in polar lipids, was found at similar levels in eggs of all three populations. Survival of walleye embryos was correlated with the concentrations of polyunsaturated long chain fatty acids. Our data suggest that deficiency in n-3 fatty acids might be associated with impaired development of walleye, and thus poor larval and juvenile viability. 041b061a72