Northern Pike (Esox Lucius) caught with "pug head" jaw deformity, usually associated with cold water temperatures during incubation.
Observation by Harold Okitkun:
In the picture you can see how the pike's mouth is deformed.
Jayde Ferguson, Fish Pathologist with the Alaska Department of Fish and Game, writes:
This looks like a deformity called pug head. It’s thought to be associated with sub-optimal incubation temperatures (or other factors during incubation) that cause an under development (hypoplasia) of the upper jaw (maxilla) so it looks like the lower jaw (mandible) is over developed. It’s common to occasionally encounter a few individuals with such a deformity within a larger population and is no cause for concern. If a large percentage of the population is affected, then it could indicate a potentially more widespread environmental factor.
Elizabeth Lindley, Assistant Environmental Health Consultant at ANTHC, writes:
Northern Pike are spring spawners, and typically spawn in grassy wetlands after or during breakup. From what I can remember (it’s been awhile since I did my pike research), spawned eggs do not do well in freezing temperatures and don’t usually survive temperatures below 3C. If this is due to sub-optimal incubation temperature, I would suspect that the individual experienced a brief freezing event. It’s not likely that the individual experienced the upper threshold of optimal temperatures during incubation, just based on the location it was harvested.
Harold Okitkun writes:
This was the only pike that was caught this way. One of the young men from here caught it and I saw his picture and asked to share it on the LEO network. There has been reports of fish caught with sores but I haven't had the chance to get any pictures. I reminded people to take pictures of any fish or animals caught so that we can report on them. If I hear or see any more abnormalities or strange happenings I will post again. Thank you for the information on the pike, this made people feel at ease with what was caught.