Fish identification can be a challenge. There are a hundred some species of fish in Nebraska. Anglers may catch maybe forty-some of those species. That does not seem too daunting, but it gets complicated by the fact that any species of fish can come in a variety of sizes and coloration is highly variable. For that reason, it is useful to know identification characteristics other than coloration or “looks”. However, it is true that we learn different species simply by looking at them.
Identification gets even more complicated when hybridization occurs. Depending on the closeness of the genetic relationship, hybridization can be common among some species of fish. Throw in the work of some mad fisheries scientists experimenting in a fish hatchery laboratory someplace and there are even more hybrids possible.
I always say that hybrid fish have a combination of characteristics from each parent species. They tend to be an intermediary form between both parent species. Have also said that identification of hybrids becomes easier when you can compare the hybrid with both parent species. Unfortunately, rarely does an angler have the opportunity to hold and examine a hybrid and one, let alone both, of its parent species. If that could occur, identification can be easier.
While catching some redear sunfish recently, I naturally caught several bluegills as well. I also dried off a redear X bluegill hybrid or three. That gave me an idea. . . .
I grabbed the camera and took some photos. With a little manipulation on the computer. . . .
Things can get even more complicated with hybrids of fish species that are related close enough that the hybrids are fertile and can reproduce with each other and with each parent species. Believe me, I am not even going to try to show you the continuum of forms that are possible under those conditions. In that case, I will tell you to make your best guess on identification. Know that the only way to be completely sure with some fish hybrids is DNA analysis. Your guess is as good as any under those circumstances.
At one time, I did some fishing and field work on a small pit in central Nebraska that had bluegills, green sunfish, and redear sunfish. I saw fish from that pit that were all three parent species and every combination of hybrids in between all three. I hated to have to guess the actual identity of some of those fish.
There are many more examples. Instead of including them here and making this blog post longer and more confusing, I promise to post more, later.
Look close at the fish you catch. Learn them, appreciate them. Correct identification is important, and it will help you enjoy them more.