blue walleye

{{Subspeciesbox

| image = Blue walleye.jpg

| image_caption =

| status = EX

| extinct = 1983

| classification_status = invalid taxon

| genus = Sander

| species = vitreus

| subspecies = glaucus

| authority = (Hubbs, 1926)

| synonyms = *Stizostedion glaucum {{small|Hubbs, 1926}}

Stizostedion vitreum glaucum {{small|Trautman, 1981}}
Sander glaucus {{small|Hubbs, 1926}}

}}

The blue walleye (Sander vitreus var. glaucus), also called the blue pike, was a unique color morph (formerly considered a subspecies) of walleye which was endemic to the Great Lakes of North America. Morphometric studies led biologists to classify the blue walleye as a separate species in 1926, although it was later downgraded to a subspecies. Listed as an endangered species by the United States in 1967, it was declared extinct in 1983.

Genetic analyses conducted in the 21st century show that the blue walleye was not genetically different from the yellow walleye (Sander vitreus), rendering the taxon invalid.

Species controversy

File:Blue morph yellow walleye.jpg

The blue walleye was long considered to be different from the yellow walleye.{{cite book|editor-last1=Bolsenga|editor-first1=S.J.|editor-last2=Herdendorf|editor-first2=Charles E.|title=Lake Erie and Lake St. Clair Handbook|location=Detroit|publisher=Wayne State University Press|date=1993|isbn=9780814324707|url=https://books.google.com/books?id=nndmmFTWkVEC|page=323}} Based on morphological study, Carl Leavitt Hubbs declared the blue walleye to be a separate species in 1926.{{cite book|last1=Wallus|first1=Robert|last2=Scott|first2=Edwin M.|chapter=Genus: Sander (Rafinesque)|title=Reproductive Biology and Early Life History of Fishes in the Ohio River Drainage. Vol. 4: Percidae - Perch, Pikeperch and Darters|editor-last1=Simon|editor-first1=Thomas P.|editor-last2=Wallus|editor-first2=Robert|location=Boca Raton, Fla.|publisher=CRC Press|date=2004|isbn=084931920X|url=https://books.google.com/books?id=Wn3LBQAAQBAJ|page=570}} The species was later downgraded to a subspecies.{{cite report|last=Bennett|first=David Henry|title=Probable Walleye (Stizostedion Vitreum) Habitation in the Snake River and Tributaries of Idaho: Research Technical Completion Report|location=Boise, Idaho|publisher=Idaho Water Resources Research Institute, University of Idaho|date=1979|oclc=5525598|page=4}}

The blue walleye was a commercially valuable fish in the Great Lakes. Populations appeared to collapse quickly in the 1950s. Between 1950 and 1957, catches in the U.S. and Canada fluctuated between {{convert|2000000|lb|kg}} and {{convert|26000000|lb|kg}} a year. In 1959, however, just {{convert|79000|lb|kg}} were caught, and in 1964 only {{convert|200|lb|kg}}.{{cite book|last=Trautman|first=Milton B.|title=The Fishes of Ohio|location=Columbus, Ohio|publisher=Ohio State University Press|date=1981|isbn=9780814202135|page=613}} The United States declared blue walleye an endangered species in 1967,{{cite book|last=Wilcove|first=David Samuel|title=The Condor's Shadow: The Loss and Recovery of Wildlife in America|location=New York|publisher=Anchor Books|date=2000|isbn=9780385498814|url=https://books.google.com/books?id=sey8NcRN_FcC|page=129}}{{cite web|url=https://ecos.fws.gov/ecp/species/E041|title=Blue pike (Stizostedion vitreum glaucum)|website=Environmental Conservation Online System|publisher=U.S. Fish & Wildlife Service|access-date=30 April 2023}}{{Federal Register|32|4001}} and extinct in 1983.{{cite book|last=Weidensaul|first=Scott|title=The Ghost With Trembling Wings: Science, Wishful Thinking, and the Search for Lost Species|location=New York|publisher=North Point Press|date=2002|isbn=9780374246648|url=https://books.google.com/books?id=cSXE6lAN9YUC|page=72}}{{Federal Register|48|39941}}

A 2014 genetic study of 1,181 preserved "historic" walleye (70 to 90 years old), blue walleye/blue pike, and modern walleye found no evidence for concluding that blue walleye/blue pike were genetically distinct from other walleye.{{cite journal|last1=Haponski|first1=Amanda E.|last2=Stepien|first2=Carol A.|author-link2=Carol Stepien|title=A population genetic window into the past and future of the walleye Sander vitreus: relation to historic walleye and the extinct 'blue pike' S. v. 'glaucus'|journal=BMC Evolutionary Biology|date=2014|volume=14|number=133|doi=10.1186/1471-2148-14-133|pmc=4229939|pmid=24941945|page=133 |doi-access=free }} This rendered the taxon invalid.{{cite book|last1=Stepien|first1=Carol A.|last2=Haponski|first2=Amanda E.|chapter=Taxonomy, Distribution, and Evolution of the Percidae|title=Biology and Culture of Percid Fishes: Principles and Practices|editor-last1=Kestemont|editor-first1=P.|editor-last2=Dabrowski|editor-first2=Konrad|editor-last3=Summerfelt|editor-first3=Robert C.|location=New York|publisher=Springer|date=2015|isbn=9789401772266|url=https://books.google.com/books?id=VZnDCgAAQBAJ|page=21}}

Occasionally, grey-blue or steel-blue walleye are caught in Lake Erie, Lake Ontario, and the Ohio River drainage.{{cite book|last=Trautman|first=Milton B.|title=The Fishes of Ohio|location=Columbus, Ohio|publisher=Ohio State University Press|date=1981|isbn=9780814202135|pages=611, 613|postscript=none}}; {{cite book|last1=Scott|first1=William B.|last2=Crossman|first2=Edwin J.|title=Freshwater Fishes of Canada. Bulletin 184|location=Ottawa|publisher=Fisheries Research Board of Canada|date=1973|oclc=256035728|access-date=April 27, 2018|url=http://www.dfo-mpo.gc.ca/Library/52369_Pt8.pdf|page=768|postscript=none}}; {{cite news|title=Fish thought extinct caught in Tennessee|work=United Press International|date=February 9, 2012|access-date=September 30, 2018|url=https://www.upi.com/Fish-thought-extinct-caught-in-Tennessee/21461328824381/|postscript=none}}; {{cite news|title=Blue pike extinct, but did they ever really exist?|work=The Coloradoan|date=March 19, 2014|access-date=September 30, 2018|url=https://www.coloradoan.com/story/news/2014/03/18/blue-pike-extinct-but-did-they-ever-really-exist/6584083/|postscript=none}}; {{cite news|last=Bowman|first=Dale|title=Blue pike, silver pike, walleye: Tracking fishing mystery and words|work=Chicago Sun-Times|date=July 11, 2016|access-date=September 30, 2018|url=https://chicago.suntimes.com/sports/blue-pike-silver-pike-walleye-tracking-fishing-mystery-words/}} Dark blue yellow perch are also sometimes caught in the same areas.{{cite book|last=Trautman|first=Milton B.|title=The Fishes of Ohio|location=Columbus, Ohio|publisher=Ohio State University Press|date=1981|isbn=9780814202135|page=612|postscript=none}}; {{cite book|last1=Scott|first1=William B.|last2=Crossman|first2=Edwin J.|title=Freshwater Fishes of Canada. Bulletin 184|location=Ottawa|publisher=Fisheries Research Board of Canada|date=1973|oclc=256035728|access-date=April 27, 2018|url=http://www.dfo-mpo.gc.ca/Library/52369_Pt8.pdf|pages=755–756}}

A turquoise-colored walleye exists in some waters of the Canadian Shield.{{cite journal|last1=Paradis|first1=Yves|last2=Magnan|first2=Pierre|title=Phenotypic variation of walleye, Sander vitreus, in Canadian Shield lakes: New insights on percid polymorphism|journal=Environmental Biology of Fishes|date=2005|volume=73|issue=4|pages=357–366|doi=10.1007/s10641-005-2261-1|s2cid=22471516|access-date=April 27, 2018|url=https://www.researchgate.net/publication/226363154}} A mucosal pigment, named "sandercyanin", was hypothesized to be the source of the color,{{cite journal|last1=Yu|first1=Chi-Li|last2=Ferraro|first2=Daniel|last3=Ramaswamy|first3=S.|last4=Schmitz|first4=Mark H.|last5=Schaefer|first5=Wayne F.|last6=Gibson|first6=David T.|title=Purification and properties of sandercyanin, a blue protein secreted in the mucus of blue forms of walleye, Sander vitreus|journal=Environmental Biology of Fishes|date=2008|volume=82|issue=1|pages=51–58|doi=10.1007/s10641-007-9252-3|s2cid=20912874}} but this has not been confirmed.{{cite journal|last1=Schaefer|first1=Wayne F.|last2=Schmitz|first2=Mark H.|last3=Blazer|first3=Vicki S.|last4=Ehlinger|first4=Timothy J.|last5=Bergese|first5=John A.|title=Localization and seasonal variation of blue pigment (sandercyanin) in walleye (Sander vitreus)|journal=Canadian Journal of Fisheries and Aquatic Sciences|date=2015|volume=72|issue=2|pages=281–289|doi=10.1007/s10641-005-2261-1|s2cid=22471516|access-date=April 27, 2018|url=http://www.nrcresearchpress.com/doi/full/10.1139/cjfas-2014-0139#.WuNmcqQvyUk|url-access=subscription}} This fish was also thought to be a separate subspecies of walleye, but genetic testing showed there is no difference between the turquoise walleye and yellow walleye.

Description

Sander vitreus "glaucus" also known as the "blue pike" is endemic to Lakes Erie and Ontario and co-occurred with Sander vitreus vitreus. It is compared to the walleye in many aspects however, the "blue pike" inhabits the deeper and cooler areas of Lake Erie but was also seen in shallow and warmer areas alongside the walleye. In comparison to the walleye the "blue pike" has a steel blue color, larger eyes placed bit higher than the walleyes eye placement, and the eye distance is smaller as well. {{Cite journal|last1=Hamponski|first1=Amanda|last2=Stepien|first2=Carol|year=2014|title=A population genetic window into the past and future of the walleye Sander vitreus: relation to historic walleye and the extinct "blue pike" S-v. "glaucus"|journal=BMC Evolutionary Biology|publication-date=17 June 2014|volume=14|pages=1–21|doi=10.1186/1471-2148-14-133|pmid=24941945|pmc=4229939|doi-access=free}}

blue walleye

Species controversy

Description

References

Further reading