Steve Knight

How old is old?

Of course, it depends on who you are talking to and what you are talking about.

That is certainly the case for fish.

A Wyoming Game and Fish Department biologist recently caught a Mackinaw trout that he helped stock. The biologist, Bill Wengert, noticed a clipped fin after landing the 23-inch fish while ice fishing on Flaming Gorge Reservoir.

When he checked stocking reports, sure enough Wengert had been on the crew that stocked the fish in the lake - in 1983.

Odds are against a fisherman catching a 25-year-old fish of any kind in Texas. It has nothing to do with fishing pressure, however.

"Cold water fish and ones living in higher latitude tend to live longer," said Craig Bonds, Texas Parks and Wildlife Department Inland Fisheries regional biologist from Tyler. "Even the same species, when you move to the south, tend to grow quicker and die sooner."

So hold old is old for a fish?

There is really only one way to deal for certain and that is to look at fish ear bones called otoliths. Like the growth rings of a tree, otoliths "rings" grow annually. Using this and other age and growth data, the department has come up with a picture of aging in Texas' waters.

"In Texas an old crappie would be 4 to 6 years old. An old largemouth bass would be 8 to 12," Bonds said.

There are cases of largemouth bass living longer. The most famous example is Ethel, the state's first ShareLunker bass. The fish lived to be 19 years old, but about half of those years were in the comfort of a tank at Bass Pro Shop.

A check of the department's ShareLunker records, however, show that while some of the big fish have been as young as 6 and as old as 13; they average 8 to 9 years old.

Going down the fisheries list, Bonds said an old white bass might be 4 or 5 years old. Its cousin, the striped bass, however, could make it to 10 or 15.

Catfish are the true old-timers of the fish world in these parts. Bonds said a channel catfish might live to be 8 to 10, while blues and flatheads can live up into the teens, maybe longer.

Living long is one thing, becoming productive is another. Fish reach spawning maturity when they reach a specific size. How old that is depends on the lake or river they are in, but based on age and growth data TPWD has a general idea.

"Generally what we see after stocking a lake (with catfish) is that we won't see recruitment come into the system until 8 to 10 years after stocking. That doesn't mean it takes that long for them to mature. It takes that long for us to be able to detect it. It takes about 6 years for a female to contribute offspring to the fishery," Bonds said.

That is one reason it can be so difficult to establish a catfish fishery. In most cases the other species are much more productive. For example, stock fingerling catfish and a largemouth bass in a lake the same year and by the time the catfish spawns for the first time the bass will have spawned four or five times and will be nearing a downhill slide.

"A female matures at about 2. Males sometimes at one. Once a female matures at 2, as she ages and obtains a larger size, she increases in egg production to a certain point," Bonds explained. He added that female bass, based on hatchery experience, generally become less productive at about 8 years old.

Like bass, female crappie mature at 2. Males mature at 1.

White bass mature even younger, explaining why a white bass fishery can go from bad to good so quickly.

"White bass females mature at 1. Females, some mature at 1 and some at 2. They grow fast down south in Texas and they have some that can reach the length limit in one year," Bonds said.

What keeps bass from being even more prolific is environmental conditions, the biggest of which is timely water flow in spawning rivers and creeks.

Bonds said the same thing that makes many of the fish species so attractive to fishermen in the south, a fast growth rate, is what causes them to live shorter lives.

"In the northern latitudes their growing season is limited compared to down her. (A bass) may not mature (in the north) until it is 4-plus. It can't gain the body mass to divert to reproductive tissue. They live longer and grow slower," he said.

"The competitive reproductive system is different from north to south," he explained.

As a research student in Virginia, Bonds said he looked at crappie there that were at least 12 and white bass that made it to 8 years old.

Bonds added that in the south, the fish grow so quickly that there is a natural selective advantage. The fish grow quickly, obtain maturity sooner, spawn a few times and then die.

Power plant reservoirs, such as Monticello, provide an extreme example of the difference between cold and hot water environments even within the state. With water temperatures that range from 80 degrees in the winter to upward of 100 in the summer, a bass' metabolism is constantly racing to keep up.

"The fish's metabolism is running on hyperactivity. They have to eat a lot of food to maintain their metabolism much less grow," Bonds said.

He adds that is a reason that when bass have been stocked in tropical climates such as Cuba that they haven't become the world record size predicted.

"Moved to tropical climates the fish grow super fish and die young before they can reach world record size," Bonds noted.

Steve Knight is the outdoor writer for the Tyler Morning Telegraph. He can be reached by calling 903-596-6277 or by e-mail at outdoor@tylerpaper.com.

Steve Knight
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