If the bite on your favorite species has been slow and inconsistent, don't blame yourself, blame the weather.

Pennsylvania Fish and Boat Commission biologists say an abnormally cool, wet spring punctuated by brief periods of heat had crappies, walleyes and other fish confused, causing reproduction to stall and sputter before finally getting on track.

"Everything we're culturing suggests fish were two weeks behind this year," said Larry Hines, the commission's manager of northern hatcheries at the Linesville facility at Pymatuning Reservoir. "Everything seemed to get backed up because water didn't warm up as quickly this year."

Hines and his team collect walleyes, muskies, channel catfish, crappies, bluegills, paddlefish and largemouth bass from a 2,500-acre sanctuary water adjacent to Pymatuning to produce stock for lakes and streams across the state. While some species are moved as egg-laden adults or newly-hatched fry to 20 different nursery ponds near the reservoir, ripe walleyes and muskies are collected in traps in early spring, and their eggs stripped and fertilized by hand in the hatchery. This year's process didn't follow the normal routine, Hines said.

"Usually, there's a kind of bell curve, where you start to slowly trap ripe fish, then it peaks and drops off. This year, it stretched out for a long time. We had a lot of mini-bell curves, if you will. It was on again, off again."

Some anglers report a similar experience. Bob Sarnese of Prospect has boated some of the biggest crappies in the state over the years and agrees the spring bite at Pymatuning and Lake Arthur was erratic.

"It might have been more than a couple of weeks late, although it's hard to tell with crappies because they don't all spawn at once," he said. "We noticed this ongoing stopping and starting. It would get to 59 degrees and the crappies would get active, then it would cool down and we'd lose them all in a couple of days. Or they'd be there in big numbers, but the water would get cold and they'd stop hitting."

The spawn for most species is driven by daylight and water temperatures. Although the lengthening days is a sure bet, temperatures are unpredictable and every species requires a specific range in order to reproduce.

"Without that, it gets to a point where fish have to do something," said Hines. "Either they'll drop their eggs in less than optimal conditions or reabsorb them, because it's unhealthy for them to hold on to them too long."

The concern about a delayed spawn is that fish will fail to grow big enough to survive winter, but Hines doesn't expect much fallout from this year's late-blooming fish.

"A couple of weeks delay isn't a big deal, and I doubt we'll see a drastic impact," he said. "A lot depends on forage. If it's a good year for forage, fish can make up for it and grow pretty quickly."

Hatchery workers fertilize nursery ponds to boost the emergence of daphnia -- a type of zooplankton that bass and walleye fry need to survive -- but a spate of warm weather earlier this spring helped spur growth in the main lake, too, Hines said.

"We lucked out in that regard. Even a few days can be enough to get things going."

The last batch of walleye fingerlings was shipped out on Friday and Hines said they were some of the nicest fish he had ever seen, in both numbers and quality. Other stock, except muskies and paddlefish, which are held all summer for fall plantings, also had been trucked to destinations across the state.

Hines was still waiting for channel catfish to spawn.

"They're a little behind," he said. "They need water in the upper 70s and it's still cool here. Fewer clouds and more sunshine would do it."

In the meantime, persistent cool temperatures can prolong the fun for anglers targeting walleyes and other coolwater species.

Terry Petrick of Imperial and his son Robbie, 15, made their first trip to Pymatuning this year on June 12.

"I'm a teacher, so that was our first opportunity to do some serious fishing," Terry Petrick said.

It was worth the wait. He released a 45-inch, 23-pound muskie trolling in 14 feet about 75 yards from the Jamestown shore and his son caught a 7-pound, 28-inch walleye in the same area two days later.

"The water was 70 to 72 degrees, probably because the overnight temperatures had been in the high 40s," Petrick added. "There were a lot of small perch in the water. It was a picture perfect day."