SCIENCE LAB SCURRY

                                        

NO DENTIST REQUIRED

Lost a tooth? A dozen teeth?

This fish has no need to worry.

If there is one place you don't want to stick your finger, it's the mouth of a Pacific lingcod. These fish, which can reach five feet in length and weigh 80 pounds, have about 500 needlelike teeth in jaw strong enough to crush crustaceans.

Having so many teeth allows these ambush predators to subdue prey  as varied as slippery squid and heavily armored crabs.

But scientists have long wondered how lingcod keep their teeth so sharp.

A new study says that the secret is their replacing about 3 percent of their teeth every day. For a lingcod, that's 20 teeth a day.

Much of what scientists know about tooth replacement in fishes comes from sharks, which have multiple rows of teeth that are constantly being replenished. But shark teeth differ in significant ways from those found in the majority of fishes, which is why the lingcod findings could help scientists better understand the phenomenon of tooth replacement in fishes.

Around 20 percent of Pacific lingcod have fluorescent green or blue meat, and scientists aren't sure why this happens. But the fish are considered a smart seafood choice even so, and are delicious when battered and fried.

But otherwise, they aren't very remarkable. Their teeth are similar to those of many other fish, which is one of the reasons ''they serve as a really nice model for studying teeth in fish,'' said Karly Cohen, a doctoral candidate at the University of Washington and a co-author of the new study. [Annie Roth]