There are many scientific links to search..
Search "chinook fecundity alaska," you will find some very interesting information on the subject... Fecundity is the number of eggs, plus the size of the eggs is variatble too... in general the increase in size and wieght of the fish the egg size and number increase too. This of course is not always true and there are many variable that play into sexual development of salmon and steelhead that may be indepent of size, and have to due w/ ocean life histories, age, and the particular differences in life histories.
Originally Posted by FishnMan
In my personal experience, I having fished chinook all over the state the Kenai kings exibit both very large egg size and very high fecundities compared to other places in Alaska and the NW.
One thing to keep in mind is the particular sexual maturity of the fish which u are comparing... Likely that the Salcha king was more sexually developed then the Kenai fish you caught, meaning if you would have caught that same Kenai fish in another month I think you opinion would have been the opposite, esp given the picture you used as reference from the very skinny Salcha king...
When you catch these same salmon in the ocean the gonads are very small and the entire body cavity and organs are absolutly lined w/ fat, conterversly in the river the body cavity is deviod of fat reserves that have all ready been used and the gonads are resonably developed....
Here are just two quick links I searched up that compare fish within the same river:
One more thing...
Salcha and Kenai kings exhibit very very different life histories and the early run Kenai king would much more closely resemble the life History of the Salcha King minus the very long and jouney up the Yukon to the Salcha....
I would guess that the upper Copper or Kuskowkim river chinook would be much more comparable to the Salcha kings... Remember that much more enegy has to be expended by fish that have long distances to travel and typically upon freshwater entrance fish that have a long distance to travel will be very sexually immature compared to Kenai late run chinook that upon fresh water entrance are comparably more mature and need only travel a short distance to their spawning grounds.