Illinois Department of Natural Resources (IDNR) biologist Frank Jakubicek holds up the Spotted Gar (Lepisosteus oculatus) specimen found in the North Branch Channel of the Chicago River in September 2014. Photo by IDNR (used with permission).
Earlier this fall (September 2014) during a routine survey on the lookout for Asian carp (Bighead and Silver Carps), Illinois Department of Natural Resources fisheries biologists instead found a Spotted Gar (Lepisosteus oculatus) in the North Branch Channel of the Chicago River. This marked the first finding of the species in the Chicago Area Waterways System (CAWS), and northwestern-most occurrence of the species in Illinois (and the Great Lakes region).
As you can imagine, we were quite excited to get involved and expound upon the implications of this find! In preparation for an upcoming more detailed commentary and new entries (finally!), we are posting some links to the media accounts of the find, as well as the National Geographic blog by Primitive Fishes author Solomon David. More to come!
Apologies for the lack of updates on this project and many others, things have been quite hectic over the past couple months with new research projects, a job transition, and more. Here is the semi-final stage of the alligator gar head project, and it will remain at this stage for a while until some other pieces of the final project can be brought together. After defrosting the gar and prying the jaws open, it was preserved in a bucket of formalin for several days. Once formalin preservation was complete, the head was removed and soaked in water for approximately 24 hours (to reduce amount of formalin). Finally, the head was dried by sitting in the sun/air-dried for several days. The final product is what you see here; the photo was taken with Instagram, which I have been experimenting with with several primitive fishes as subjects…album coming soon; and you can see some other photos on our facebook page.–
-via Sara Strassman & Upper Mississippi River Conservation Committee
This is an example of a combination of unusual genetic conditions expressed in fishes and other organisms. Xanthochroism is a condition where all pigments other than yellow and orange are absent or minimally expressed. Melanism is an excess of dark pigmentation. This fish is a combination of the two conditions; it has previously been observed in gars, and the combination of colors seems to be most apparent during spawning season.