ESPN Freshwater

Since the first cave drawings were met with a neighbor's unibrow furrowed in skepticism, the necessity to measure and record a flipping underwater creature has been an integral part of every angler. And not just for bragging rights. Our internal fish data gathering processor needs a number.

But what to measure? Some fish sizes communicate better with length; others, weight. Which would you rather catch, a largemouth bass that is 21 inches ... or one that weighs 5 pounds?

You bet your sweet bippy. Robert Earl Keen didn't sing about catching a "21-Inch Bass." Anyone get the length of Iaconelli's 12 pound, 13 ounce gut-wrencher at Amistad? Exactly.

We measure the length of dinks to stay legal. But because it is a largemouth bass we want — no, need to know how much it weighed. One of the few lift-friendly fish, bass provide us with a handy big-mouth lip handle. Lip a pike and you're going to bleed.

A fisheries professional would have the proper instruments to record everything for every fish species. Date, time, water temperature, turbidity, as well as perhaps stomach contents and anatomical structures (otoliths, scales, spines) to age the fish back in the lab. Sample the population enough, and you have a foundation for managing the fishery.

That's great. But the recreational angler still wants to know how big the thing is.

There seem to be two main schools of thought with regard to describing size.

The Length Crowd tends to be influenced by trout. Other quarry might include smallmouth bass, pike and walleye that prefer cooler or flowing water. Their disdain for heft applies even to their gear: 2-pound tippets, 4-weight rods, dainty lures made from feathers.

Nathan Kennedy, a blogger for tvangler.com, agrees.

"When trout fishermen fish for other species, they often hang onto the length measurement," he told me by e-mail. "For example, I hear them talk about catching a 20-inch smallmouth bass or whatever. When bass fishermen take up trout fishing, they talk about weight, at least for awhile. It's almost pointless to talk about weight when you're catching small mountain trout that weigh just a few ounces, but there's a big difference to a fly fisherman between a 6-inch brook trout and a 10-inch one."

The Weight Crowd tends to pursue largemouth bass, catfish and other fish that favor still, warmer water. Weighters throw lures the size of 6-inch brook trout and use 50-pound line to horse fish through aquatic weeds and brush. To them, mass equals merit. They look for excuses to lug around car batteries.

(We have to acknowledge one more subset: Girth Gang, a faction of the Length Crowd. As much as I love the word, "girth" alone doesn't really communicate overall fish size to most anglers. If distance around the largest midsection of a fish is a measurement you hang your hat on, you're either a fisheries biologists working down the list, or you work for UPS.)

Length is a cinch to ascertain, assuming you have a measuring board or tape measure. If not, you'll have to unfold your pocketknife and carve a mark in your arm to measure later.

The big perk of length is that it can be communicated immediately by the international gesture of holding your two hands apart. Try to indicate weight similarly:

"How big was it?"

(Pantomime lifting an anvil.)

"What?!"

"Here, hold my hiking boots. That's how big that fish was."

Kind of loses something.

Most fish have "indeterminate" growth. That is, even old fish have the capability to grow longer. Once it achieves length, the fish is not going to shrink. Weight, though, fluctuates — just ask Oprah. Changes in temperature and water conditions, or the sheer stress of the spawn, can shrink a bass. Plus just weighing the thing — with a rusty scale, on a bobbing boat — is enough to make you pine for those slashmarks on your arm.

Also, the fish must actually have weight. You can read a newspaper through a 9-inch crappie fillet. There are no minimum weights for harvest restrictions. Smaller fish have a higher surface area of dripping water for weight than larger fish, so measurement is less precise.

Keith Sutton, also via e-mail, told me he believes "worthy catches always are measured by weight." Indeed, even though minimum size regulations are always in length, record fish are almost always listed in weight. To be truly impressive, length should be in units greater than mere inches. Like the 5-foot minimum of the Madfin Shark Series.

There are some exceptions. Like muskies.

I can't remember my cell phone number (how many times do I dial myself?) but I don't think I'll ever forget the length of my first (and only) muskie: 45 1/2 inches. And don't think I'm going to leave off that half-inch.

When Jeremy Wiser hauled my fish into the boat and laid it along his measuring gunnel, his buddy Steve said, "Here's what you do. You take your knife and carve a notch in the boat right there and you say, 'This is the length to beat!'"

Smith Mountain Lake, site of the last Bassmaster Elite Series tournament, is home to muskellunge. Imagine, instead of 20 pounds of fish a day, catching 20 feet of fish a day. Catch the length of your boat or you're cut.

Now if you'll excuse me, some cut-up fisherman just e-mailed me to say he caught a 30-inch catfish, and I have to figure out how big it was.

Andy Whitcomb, a freelance writer and designer, can be reached through his Web site, justkeepreeling.com.