No country for old fish - 03/30/08 11:45 AM
The Dallas Morning News10:16 PM CDT on Saturday, March 29, 2008
No country for old fish
Bass, crappie don't have long lives in Texas lakes
By Ray Sasser
According to news reports, Bill Wingert, a Wyoming fisheries biologist, caught a 23-inch Mackinaw trout while ice fishing at Flaming Gorge Reservoir earlier this year. A clipped fin on the fish jarred Wingert's memory. Biologists sometimes clip the fins of stocked fish in unique ways so they can identify year classes of game fish that are harvested.
When he looked back through stocking records, Wingert was not surprised to find that he had been on the crew that stocked that particular trout. He was surprised to discover that the fish had been stocked in 1983.
At Lake Fork a couple of years ago, I was fishing early one morning with Brian Duplechain when a bass struck at my topwater plug and missed. I made 15 or 20 more casts across the same spot before the fish hit again. The guide and I both saw the bite and we both said "big fish" at virtually the same time.
After a lackluster fight that lasted mere seconds, I led the bigmouth into Duplechain's landing net. The fish had probably been an 8-pounder at the height of its career but it was now long, lean and one-eyed, a battle-scarred senior citizen that weighed about 5 pounds.
It fought so little that I joked that this fish had probably been caught 10 times and obviously knew the routine. If it just swam to the boat as quickly as possible, it would be gently released to continue its search for breakfast.
Craig Bonds doubts that a fish has the mental capacity for such an advanced thought. Bonds is a biologist and regional fisheries director for Texas Parks and Wildlife. He said it was much more likely that the fish I caught fought weakly because it was old and worn out.
Even so, the fish may have been no more than 10 years old. Unlike a Wyoming trout, most Texas game fish are not long-lived.
"In western Virginia, I once aged a crappie that was 16 years old," Bonds said. "The fish's age was confirmed by two other biologists. Fish in northern latitudes tend to grow slower because of the brief growing season. The 16-year-old crappie was about 12 inches long. It takes them longer to become sexually mature. As a result, fish that live in cold water tend to live longer than fish in Texas."
Bonds said most legal-sized Texas crappie (10 inches, minimum size) are 2 to 3 years old. White bass grow even faster. A 10-inch white bass caught in Texas may only be 1 year old and is probably no older than 2.
Most minimum size limits set for Texas game fish are based on protecting the fish through at least one spawning season. Unlike most animals, fish continue to grow as long as they're getting enough to eat. The Lake Fork bass that I caught was past her prime and half blind. She probably had trouble catching food.
Bonds said that once fish reach sexual maturity, their growth rates tend to slow. Females are stressed caused by reproduction. In winter and spring, their nutrition is diverted to egg development rather than body condition.
Because of the Budweiser ShareLunker program, Texas has reams of big bass records. By counting growth rings from a scale taken from each lunker, biologist figure that most of the 13 pounds-plus lunkers are 8 to 9 years old. The youngest was 6 and the oldest was 13.
Bonds said growth rings on scales are an inefficient way to age a fish, but it's the only way to age a bass without killing the fish. The best method is to count growth rings on an otolith, a fish's ear bone.
The otolith taken from the state record blue catfish caught from Lake Texoma in 2004 showed the 121.5-pounder to be 23 to 25 years old. Catfish don't have scales but a rough age estimate is possible by examining its pectoral spines. At the Texas Freshwater Fisheries Center, there is a replica of a flathead catfish that was estimated at 40 years old.
Bonds said the longest- lived common fish in Texas are probably those that we know little about – fish like alligator gar and common carp. Alligator gar are the biggest of the state's freshwater species and may exceed 300 pounds.
"Mother Nature has an interesting way of assuring survival of the species," Bonds said. "In cold waters, where fish grow slowly and mature slowly, they live longer. In warm waters, where fish grow fast and mature quickly, their life expectancy is not as long."
Ray Sasser
03-29-08
