06-02-2006, 12:23 PM
I had this emailed to me and thought it was worthy of posting....
Trophy fish likely are also quite old
By Bob Frye
TRIBUNE-REVIEW OUTDOORS EDITOR
Sunday, May 28, 2006
Size vs. age
So just how old is that fish on the end of your line? Here's a look at the weights and ages, on average, of species of fish at different lengths in Pennsylvania at this time of year.
• A 30-inch muskie will weigh 6.5 pounds and be 3.8 years old. A 50-inch muskie will weigh 36.9 pounds and be 20.1 years old.
• A 12-inch largemouth bass will weight 0.8 pound and be 3.8 years old. A 20-inch largemouth will weigh 4.3 pounds and be 10.6 years old.
• A 6-inch bluegill will weigh 0.1 pound and be 3.1 years old. A 10-inch bluegill will weigh 0.7 pound and be 15.1 years old.
• An 8-inch crappie will weigh 0.3 pound and be 3.4 years old. A 16-inch crappie will weigh 2.6 pounds and be more than 18.8 years old.
• A 24-inch northern pike will weigh 3.1 pounds and be 4.8 years old. A 40-inch pike will weigh 16.1 pounds and be 11.6 years old.
• A 15-inch walleye will weigh 1.1 pounds and be 3.1 years old. A 30-inch walleye will weigh 10.8 pounds and be more than 18.5 years old.
The state-record black crappie that Richard Pino of Covington pulled from Hammond Lake in Tioga County exactly five years ago today did not have a gray beard on it.
But perhaps it should have.
That fish -- which weighed 4 pounds, 2.88 ounces and stretched a hair longer than 19 1/4 inches -- had likely been swimming in that lake for nearly two decades. According to Pennsylvania Fish and Boat Commission estimates, a crappie of that size caught at this time of year was likely more than 18.8 years old.
"You can see some fairly old specimens," said Bob Lorantas, warmwater unit leader for the Fish and Boat Commission. "With walleyes for example, the norm might be to see fish that are 4, 5 or 6 years old. But we've had them up to 18 and 20 years old, too."
Fisheries biologists determine the age of individual fish by collecting four or five scales, then examining them under a microscope. Each individual scale adds a ridge -- much like a tree adds a ring -- for every year of life. By counting the ridges on a scale, biologists can tell how old a fish is.
That technique has been around since the 1930s -- rock bass were one of the first species to be examined that way -- and Fish and Boat Commission biologists still use it today to gauge the age structure of fish populations when surveying particular waterways.
It might surprise anglers to learn just how old the fish they're catching really are. A 6-inch rock bass, for example, may seem small, and will indeed weigh just one-tenth of a pound. That fish will already be 2.4 years old, though. If it lives to reach 9 inches, it's likely 9 years old. At 12 inches, it's probably more than 12 years old.
Catch a 12-inch smallmouth bass this month and chances are it's about 4.2 years old. Catch a 20-incher and you can bet it's about 11.9 years old.
That's a long time to survive in the wild, which explains why really big fish are so rare, Lorantas said.
"A good rule of thumb is that there's probably a 50 percent reduction in the number of fish of a certain age every year," he said. "If you start out with 1,000 rock bass at age 1, there might be 500 by the time they reach age 2. By the time they reach age 3, there might be 250, and 125 by age 4 and so on.
"That's why there are fewer big fish in a waterway than there are smaller ones. The older the fish, the rarer the fish."
There are a lot of reasons that a fish might live to reach an advanced age. It could be that the fish is genetically predisposed to ward off disease. It could be that it lives in an inaccessible place that make its less vulnerable to predation. It could be that it's learned to avoid anglers and their offerings.
Most likely, though, it's a combination of all those things, Lorantas said.
"Certainly, the ones that live to reach older, larger sizes are just less vulnerable overall. Whether that's by chance or learning, who really knows?" he said.
Bguy64
[signature]
Trophy fish likely are also quite old
By Bob Frye
TRIBUNE-REVIEW OUTDOORS EDITOR
Sunday, May 28, 2006
Size vs. age
So just how old is that fish on the end of your line? Here's a look at the weights and ages, on average, of species of fish at different lengths in Pennsylvania at this time of year.
• A 30-inch muskie will weigh 6.5 pounds and be 3.8 years old. A 50-inch muskie will weigh 36.9 pounds and be 20.1 years old.
• A 12-inch largemouth bass will weight 0.8 pound and be 3.8 years old. A 20-inch largemouth will weigh 4.3 pounds and be 10.6 years old.
• A 6-inch bluegill will weigh 0.1 pound and be 3.1 years old. A 10-inch bluegill will weigh 0.7 pound and be 15.1 years old.
• An 8-inch crappie will weigh 0.3 pound and be 3.4 years old. A 16-inch crappie will weigh 2.6 pounds and be more than 18.8 years old.
• A 24-inch northern pike will weigh 3.1 pounds and be 4.8 years old. A 40-inch pike will weigh 16.1 pounds and be 11.6 years old.
• A 15-inch walleye will weigh 1.1 pounds and be 3.1 years old. A 30-inch walleye will weigh 10.8 pounds and be more than 18.5 years old.
The state-record black crappie that Richard Pino of Covington pulled from Hammond Lake in Tioga County exactly five years ago today did not have a gray beard on it.
But perhaps it should have.
That fish -- which weighed 4 pounds, 2.88 ounces and stretched a hair longer than 19 1/4 inches -- had likely been swimming in that lake for nearly two decades. According to Pennsylvania Fish and Boat Commission estimates, a crappie of that size caught at this time of year was likely more than 18.8 years old.
"You can see some fairly old specimens," said Bob Lorantas, warmwater unit leader for the Fish and Boat Commission. "With walleyes for example, the norm might be to see fish that are 4, 5 or 6 years old. But we've had them up to 18 and 20 years old, too."
Fisheries biologists determine the age of individual fish by collecting four or five scales, then examining them under a microscope. Each individual scale adds a ridge -- much like a tree adds a ring -- for every year of life. By counting the ridges on a scale, biologists can tell how old a fish is.
That technique has been around since the 1930s -- rock bass were one of the first species to be examined that way -- and Fish and Boat Commission biologists still use it today to gauge the age structure of fish populations when surveying particular waterways.
It might surprise anglers to learn just how old the fish they're catching really are. A 6-inch rock bass, for example, may seem small, and will indeed weigh just one-tenth of a pound. That fish will already be 2.4 years old, though. If it lives to reach 9 inches, it's likely 9 years old. At 12 inches, it's probably more than 12 years old.
Catch a 12-inch smallmouth bass this month and chances are it's about 4.2 years old. Catch a 20-incher and you can bet it's about 11.9 years old.
That's a long time to survive in the wild, which explains why really big fish are so rare, Lorantas said.
"A good rule of thumb is that there's probably a 50 percent reduction in the number of fish of a certain age every year," he said. "If you start out with 1,000 rock bass at age 1, there might be 500 by the time they reach age 2. By the time they reach age 3, there might be 250, and 125 by age 4 and so on.
"That's why there are fewer big fish in a waterway than there are smaller ones. The older the fish, the rarer the fish."
There are a lot of reasons that a fish might live to reach an advanced age. It could be that the fish is genetically predisposed to ward off disease. It could be that it lives in an inaccessible place that make its less vulnerable to predation. It could be that it's learned to avoid anglers and their offerings.
Most likely, though, it's a combination of all those things, Lorantas said.
"Certainly, the ones that live to reach older, larger sizes are just less vulnerable overall. Whether that's by chance or learning, who really knows?" he said.
Bguy64
[signature]