When water temperatures rise in late spring or early summer, crappie begin to search for nesting spots. The female drops from 20,000 to 80,000 eggs, and the male spreads his cloud of sperm.
For a few days, males aggressively chase and bite potential predators. But only a few crappie fry will grow to minnow size.
The rest will be eaten by bugs, turtles, frogs, birds — even by their parents.
All that leads to Bill Pouder's question: At what size do crappie lay those eggs?
"That's never been documented in Florida," said Pouder, the Florida Fish and Wildlife Conservation Commission's Southwest Regional Fisheries administrator.
In northern states, crappie — also called brim, perch, sunfish, speckled bass or calico bass — spawn at 10 inches long.
"But the seasons are so different down here in Florida," said Pouder, based in Lakeland.
In warm water, where food is constantly available, fish may grow all year and reach spawning length earlier — maybe 8 or 9 inches. That's an integral part of his question.
So on Dec. 3, FWC and the Friends of Istokpoga Lake Association sponsored the Crappie Fishing Rodeo. Participants caught 420 fish; each received a unique yellow tag about the length of a pencil lead that included contact information and a reward value. Then each fish was returned to the lake.
Large crappie usually measure 15 or 16 inches. That's 2 to 3 pounds. Some fishermen throw back any crappie less than 10 inches, some keep anything big enough for the frying pan, so Pouder is leading a study to determine at what length fishermen harvest crappie.
"Eighty percent of anglers are pretty self-regulating," he said. They realize the lake's ecosystem needs reproducing females.
But the flaky white meat of the crappie makes it one of the tastiest freshwater fish.
Istokpoga is one of Florida's best crappie fishing lakes, but the FWCC got complaints of a population decline in the past three or four years. The 2011 reports were better.
Crappie are difficult to manage, Pouder said, so the reason for those swings is unclear: Maybe it's a normal boom-and-bust cycle, maybe it's the water temperature, maybe it's too much or too little vegetation.
As the weather warms and fishermen begin to return data from the tagged fish, it will go into a computer model.
"The goal of this study is determine how we can increase yields for the angler," Pouder said. His best guess today is that Florida crappie reproduce at 8 inches. But if the FWC can determine the reproduction length and communicate that to fishermen, yields may go up.
When a yellow-tagged fish is caught, anglers are asked to cut the tag from the dorsal fin, call a phone number, and answer questions such as the tag number, the fish's length and whether it was released or kept.
The tag should be placed in an envelope and returned to the FWC.
A reward will be sent; Pouder can't reveal the amount.
"We don't want people to go out there just to catch a tagged fish and get the reward."
Call Pouder at (863) 648-3805 or visit www.istokpoga.org.