Sunday, January 31, 2010


Production of Sandercyanin is seasonal and peaks in late summer. The graph plots absorbance of Sandercyan by date and indicates peak production in late summer all three years. The photo shows jars of slime from individual walleye captured in both March and August indicating greater production of blue pigment in August.


Blue pigment (Sandercyanin) is produced in membrane-bounded vesicles (440x) just posterior (toward tail) to each dorsal spine and next to an adjacent blood vessel.

Tuesday, March 04, 2008


Blue walleye of Canada are genetically different than the extinct "blue pike" of Lake Erie. They are albino for yellow color and have blue color in the mucous of their skin. The blue color forms on the dorsal (upper) part of the body and is particulary noticable in the two dorsal fins and the upper part of the tail.

Research Update

January 31, 2010

1. Two factors contribute to the blue color in walleye:
a. lack of yellow pigment in the skin of the fish.
b. presence of blue pigment in the skin mucous of the fish.

2. We have identified the blue pigment in the mucous as a new protein never before described in the literature. We have named the pigment "Sandercyanin". Sander is the genus name for walleye and cyanin means blue in Greek.

3. Sandercyanin consists of a large lipocalin protein which carries "biliverdin". Biliverdin is a normal excretory product secreted in urine of all vertebrate animals. It forms from the breakdown of "heme", a blood protein.

4. Sandercyanin occurs in the mucous of walleye in many lake and river systems in Ontario, Quebec and Manitoba. It is equally present in both blue and yellow walleye in any given lake or river system.

5. Sandercyanin appears to be moving south across the Canadian-U.S. boarder into upper Minnesota and upper Michigan.

6. Sandercyanin does not harm the health or taste of the fish.

7. Sandercyanin is produced seasonally, with more in summer than winter. It is produced only on the dorsal (upper) part of the fish, above the lateral line. Specifically, Sandercyanin is produced on a line just posterior (toward tail) to each spine in the dorsal fins.

8. One factor that causes the breakdown of heme to biliverdin is exposure to ultraviolet (UV) radiation from the sun. The earth is normally protected from UV radiation by ozone in the upper atmosphere. In recent years ozone "holes" have been noted over both the north and south poles as a result of CFCs (chlorofluorocarbons) entering the atmosphere. In some species of animals, biliverdin is known to act as a photo-protectant.

9. It is possible that walleye in Canada use, as a sun screen, the very chemical which forms in their blood from exposure to too much sun. This conclusion is still only speculation but it is our best hypothesis.

Tuesday, March 21, 2006

'Blue Walleye' Makes News

Our work was recently cited in a March 19, 2006 article in the St. Paul Pionner Press. Read the Article Here

Wednesday, March 08, 2006

Sighting Instructions

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Wednesday, February 08, 2006

Sightings is dedicated toward serving anglers, scientists and researchers. If you have seen blue walleye please share your findings with us by adding the following information in comment to this posting:

GPS (optional):
Outfitter/Lodge (optional):
Number Caught:
Average Size (inches):
Date Caught (month/day/year):
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Thank you!

Sunday, January 15, 2006

Mucous Sample Procedure

Blue walleye, and regular walleye from the same lake, will have blue colored protein in the mucous of their skin.

1) Gently remove the thin layer of blue mucous ("blue slime") from the dorsal side of the fish, moving your knife from anterior to posterior, or head to tail. Be careful not to remove the scales from the specimen.

2) Deposit the blue slime into a small bottle filled partially with water. Be sure to keep the contents of the bottle cool in temperature.

3) Send your sample to the following address:

Dr. Wayne Schaefer
University of Wisconsin - Washington County
400 University Drive
West Bend, WI 53095

View Instructional Video
(101 MB, 2 minutes)